1
|
Zhang W, Kittlaus E, Savchenkov A, Iltchenko V, Yi L, Papp SB, Matsko A. Monolithic optical resonator for ultrastable laser and photonic millimeter-wave synthesis. COMMUNICATIONS PHYSICS 2024; 7:177. [PMID: 38845615 PMCID: PMC11150148 DOI: 10.1038/s42005-024-01660-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Accepted: 05/16/2024] [Indexed: 06/09/2024]
Abstract
Optical resonators are indispensable tools in optical metrology that usually benefit from an evacuated and highly-isolated environment to achieve peak performance. Even in the more sophisticated design of Fabry-Perot (FP) cavities, the material choice limits the achievable quality factors. For this reason, monolithic resonators are emerging as promising alternative to traditional designs, but their design is still at preliminary stage and far from being optimized. Here, we demonstrate a monolithic FP resonator with 4.5 cm3 volume and 2 × 105 finesse. In the ambient environment, we achieve 18 Hz integrated laser linewidth and 7 × 10-14 frequency stability measured from 0.08 s to 0.3 s averaging time, the highest spectral purity and stability demonstrated to date in the context of monolithic reference resonators. By locking two separate lasers to distinct modes of the same resonator, a 96 GHz microwave signals is generated with phase noise -100 dBc/Hz at 10 kHz frequency offset, achieving orders of magnitude improvement in the approach of photonic heterodyne synthesis. The compact monolithic FP resonator is promising for applications in spectrally-pure, high-frequency microwave photonic references as well as optical clocks and other metrological devices. ©2024. All rights reserved.
Collapse
Affiliation(s)
- Wei Zhang
- Jet Propulsion Laboratory California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 USA
| | - Eric Kittlaus
- Jet Propulsion Laboratory California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 USA
| | - Anatoliy Savchenkov
- Jet Propulsion Laboratory California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 USA
| | - Vladimir Iltchenko
- Jet Propulsion Laboratory California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 USA
| | - Lin Yi
- Jet Propulsion Laboratory California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 USA
| | - Scott B. Papp
- National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305 USA
| | - Andrey Matsko
- Jet Propulsion Laboratory California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 USA
| |
Collapse
|
2
|
Tsai YK, Liao ZX, Lin YX, Chen HS, Huang JJS, Wang PH, Wei CC, Chang YC, Hung Y, Shi JW. Linearization of wavelength sweeping lasers for the construction of 4-D FMCW LiDAR images of slow-moving objects using baseband beat note signals. OPTICS EXPRESS 2024; 32:20401-20411. [PMID: 38859152 DOI: 10.1364/oe.524443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 05/10/2024] [Indexed: 06/12/2024]
Abstract
A FMCW LiDAR system of both the distributed feedback laser and external cavity laser is established in baseband beat notes, rather than up-conversion to an intermediate frequency to exclude flicker noise. Meanwhile, utilizing fast-scanning MEMS mirrors, high-quality real-time (1 fps) 4-D images of the slow-moving object (10 mm/s) can be directly constructed at the baseband with a central frequency as low as 100 kHz and a small Doppler shift. The proposed LiDAR architecture based on such a low-frequency baseband significantly improves the optical power budget on the transmitter side and eliminates the costly high-speed sampling circuits on the receiver side.
Collapse
|
3
|
Tebeneva TS, Lobanov VE, Chermoshentsev DA, Min'kov KN, Kaplunov IA, Vinogradov II, Bilenko IA, Shitikov AE. Crystalline germanium high-Q microresonators for mid-IR. OPTICS EXPRESS 2024; 32:15680-15690. [PMID: 38859213 DOI: 10.1364/oe.521499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 03/31/2024] [Indexed: 06/12/2024]
Abstract
High-quality-factor optical microresonators have become an appealing object for numerous applications. However, the mid-infrared band experiences a lack of applicable materials for nonlinear photonics. Crystalline germanium demonstrates attractive material properties such as high nonlinear refractive index, large transparency window including the mid-IR band, particularly long wave multiphonon absorption limit. Nevertheless, the reported optical losses in germanium microresonators might not allow the potential of the Ge-based devices to be revealed. In this study, we report the fabrication of germanium microresonators with radii of 1.35 and 1.5 mm, exhibiting exceptional quality factors (Q-factors) exceeding 20 million, approaching the absorption-limited values at a wavelength of 2.68 µm. These Q-factors are a hundred times higher than previously reported, to the best of our knowledge. We measured the two-photon absorption coefficient combined with free-carrier absorption leveraging the high-Q of the resonators (obtained βTPA = (0.71 ± 0.12) · 10-8 m/W at 2.68 µm). This research underscores the potential of whispering gallery mode microresonators as valuable tools for measuring absorption coefficients at different wavelengths, providing a comprehensive analysis of various loss mechanisms. Furthermore, the exceptional Q-factors observed in germanium microresonators open intriguing opportunities for the advancement of germanium-based photonics within the mid-infrared spectral band.
Collapse
|
4
|
Ousaid SM, Bourcier G, Fernandez A, Llopis O, Lumeau J, Moreau A, Bunel T, Conforti M, Mussot A, Crozatier V, Balac S. Low phase noise self-injection-locked diode laser with a high-Q fiber resonator: model and experiment. OPTICS LETTERS 2024; 49:1933-1936. [PMID: 38621044 DOI: 10.1364/ol.514778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 03/17/2024] [Indexed: 04/17/2024]
Abstract
Low phase noise and narrow linewidth lasers are achieved by implementing self-injection locking of a DFB laser on two distinct fiber Fabry-Perot resonators. More than 45 dB improvement of the laser phase or frequency noise is observed when the laser is locked. In both cases, a frequency noise floor below 1 Hz2/Hz is measured. The integrated linewidth of the best of the two lasers is computed to be in the range of 400 Hz and appears to be dominated by vibration noise close to the carrier. The results are then compared with a model based on the retro-injected power and the Q factors ratio between the DFB laser and the resonator. This straightforward model facilitates the extraction of the theoretical performance of these sources close to the carrier, a characteristic still hidden by vibration noise.
Collapse
|
5
|
Liu P, Zhao Y, Wang X, Ni J, Dai Z. Study on lattice dynamics and thermal conductivity of fluorite AF 2 (A = Ca, Sr, Ba) based on first principles calculations. Phys Chem Chem Phys 2024; 26:10868-10879. [PMID: 38525602 DOI: 10.1039/d4cp00201f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
Fluorite materials have received particular attention in electron optics due to their favorable optical properties. However, further exploration of these materials in the thermoelectric (TE) field is hampered by the lack of studies on their lattice thermal transport properties. In this work, we use first-principles calculations, combined with self-consistent phonon theory, compressive sensing lattice dynamics and the Boltzmann transport equation, to study the microscopic mechanism of lattice thermal transport properties in AF2 (A = Ca, Sr, Ba) with a fluorite structure. We investigate the effects of three-phonon and four-phonon scattering and quartic anharmonic renormalization of phonon frequencies on this system. The results show that the bonding strength of atoms A (Ca, Sr, and Ba) plays an important role in the thermal transport process, and the third-order anharmonicity also plays an important role in this system. Meanwhile, the role of the quartic anharmonicity cannot be ignored. Our findings not only fill in the gaps in the study of lattice thermal transport of fluorite materials, but also deepen the comprehensive understanding of the high κL value of fluorite materials.
Collapse
Affiliation(s)
- Peipei Liu
- Department of Physics, Yantai University, Yantai 264005, People's Republic of China.
| | - Yinchang Zhao
- Department of Physics, Yantai University, Yantai 264005, People's Republic of China.
| | - Xichang Wang
- Department of Physics, Yantai University, Yantai 264005, People's Republic of China.
| | - Jun Ni
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
- Frontier Science Center for Quantum Information, Beijing 100084, People's Republic of China
| | - Zhenhong Dai
- Department of Physics, Yantai University, Yantai 264005, People's Republic of China.
| |
Collapse
|
6
|
Idjadi MH, Kim K, Fontaine NK. Modulation-free laser stabilization technique using integrated cavity-coupled Mach-Zehnder interferometer. Nat Commun 2024; 15:1922. [PMID: 38429298 PMCID: PMC10907685 DOI: 10.1038/s41467-024-46319-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 02/22/2024] [Indexed: 03/03/2024] Open
Abstract
Stable lasers play a significant role in precision optical systems where an electro-optic laser frequency stabilization system, such as the Pound-Drever-Hall technique, measures laser frequency and actively stabilizes it by comparing it to a frequency reference. Despite their excellent performance, there has been a trade-off between complexity, scalability, and noise measurement sensitivity. Here, we propose and experimentally demonstrate a modulation-free laser stabilization method using an integrated cavity-coupled Mach-Zehnder interferometer as a frequency noise discriminator. The proposed architecture maintains the sensitivity of the Pound-Drever-Hall architecture without the need for any modulation. This significantly simplifies the architecture and makes miniaturization into an integrated photonic platform easier. The implemented chip suppresses the frequency noise of a semiconductor laser by 4 orders-of-magnitude using an on-chip silicon microresonator with a quality factor of 2.5 × 106. The implemented passive photonic chip occupies an area of 0.456 mm2 and is integrated on AIM Photonics 100 nm silicon-on-insulator process.
Collapse
Affiliation(s)
| | - Kwangwoong Kim
- Nokia Bell Labs, 600 Mountain Ave, Murray Hill, NJ, 07974, USA
| | | |
Collapse
|
7
|
Takamizawa A. Continuous frequency tuning of an external cavity diode laser significantly beyond the free spectral range by sweeping the injection current. OPTICS EXPRESS 2024; 32:774-784. [PMID: 38175097 DOI: 10.1364/oe.506528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 12/10/2023] [Indexed: 01/05/2024]
Abstract
In this study, the focus is on continuously tuning an external cavity diode laser equipped with an antireflection-coated laser diode over a 14.8 GHz range, 4.5 times larger than the free spectral range, using only injection current sweeps. In contrast, the absence of antireflection coating led to a tuning range of only one-fifth of the free spectral range, accompanied by hysteresis on mode hops. Theoretical analysis of this observed hysteresis suggests that broad tuning can be achieved when the longitudinal modes of the solitary laser diode are eliminated through the antireflection coating.
Collapse
|
8
|
Xiang C, Jin W, Terra O, Dong B, Wang H, Wu L, Guo J, Morin TJ, Hughes E, Peters J, Ji QX, Feshali A, Paniccia M, Vahala KJ, Bowers JE. 3D integration enables ultralow-noise isolator-free lasers in silicon photonics. Nature 2023; 620:78-85. [PMID: 37532812 PMCID: PMC10396957 DOI: 10.1038/s41586-023-06251-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 05/23/2023] [Indexed: 08/04/2023]
Abstract
Photonic integrated circuits are widely used in applications such as telecommunications and data-centre interconnects1-5. However, in optical systems such as microwave synthesizers6, optical gyroscopes7 and atomic clocks8, photonic integrated circuits are still considered inferior solutions despite their advantages in size, weight, power consumption and cost. Such high-precision and highly coherent applications favour ultralow-noise laser sources to be integrated with other photonic components in a compact and robustly aligned format-that is, on a single chip-for photonic integrated circuits to replace bulk optics and fibres. There are two major issues preventing the realization of such envisioned photonic integrated circuits: the high phase noise of semiconductor lasers and the difficulty of integrating optical isolators directly on-chip. Here we challenge this convention by leveraging three-dimensional integration that results in ultralow-noise lasers with isolator-free operation for silicon photonics. Through multiple monolithic and heterogeneous processing sequences, direct on-chip integration of III-V gain medium and ultralow-loss silicon nitride waveguides with optical loss around 0.5 decibels per metre are demonstrated. Consequently, the demonstrated photonic integrated circuit enters a regime that gives rise to ultralow-noise lasers and microwave synthesizers without the need for optical isolators, owing to the ultrahigh-quality-factor cavity. Such photonic integrated circuits also offer superior scalability for complex functionalities and volume production, as well as improved stability and reliability over time. The three-dimensional integration on ultralow-loss photonic integrated circuits thus marks a critical step towards complex systems and networks on silicon.
Collapse
Affiliation(s)
- Chao Xiang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA.
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China.
| | - Warren Jin
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
- Anello Photonics, Santa Clara, CA, USA
| | - Osama Terra
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
- Primary Length and Laser Technology Lab, National Institute of Standards, Giza, Egypt
| | - Bozhang Dong
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Heming Wang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Lue Wu
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA, USA
| | - Joel Guo
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Theodore J Morin
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Eamonn Hughes
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Jonathan Peters
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Qing-Xin Ji
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA, USA
| | | | | | - Kerry J Vahala
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA, USA
| | - John E Bowers
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA.
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, USA.
| |
Collapse
|
9
|
Alkhazraji E, Chow WW, Grillot F, Bowers JE, Wan Y. Linewidth narrowing in self-injection-locked on-chip lasers. LIGHT, SCIENCE & APPLICATIONS 2023; 12:162. [PMID: 37380663 DOI: 10.1038/s41377-023-01172-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 04/25/2023] [Accepted: 04/26/2023] [Indexed: 06/30/2023]
Abstract
Stable laser emission with narrow linewidth is of critical importance in many applications, including coherent communications, LIDAR, and remote sensing. In this work, the physics underlying spectral narrowing of self-injection-locked on-chip lasers to Hz-level lasing linewidth is investigated using a composite-cavity structure. Heterogeneously integrated III-V/SiN lasers operating with quantum-dot and quantum-well active regions are analyzed with a focus on the effects of carrier quantum confinement. The intrinsic differences are associated with gain saturation and carrier-induced refractive index, which are directly connected with 0- and 2-dimensional carrier densities of states. Results from parametric studies are presented for tradeoffs involved with tailoring the linewidth, output power, and injection current for different device configurations. Though both quantum-well and quantum-dot devices show similar linewidth-narrowing capabilities, the former emits at a higher optical power in the self-injection-locked state, while the latter is more energy-efficient. Lastly, a multi-objective optimization analysis is provided to optimize the operation and design parameters. For the quantum-well laser, minimizing the number of quantum-well layers is found to decrease the threshold current without significantly reducing the output power. For the quantum-dot laser, increasing the quantum-dot layers or density in each layer increases the output power without significantly increasing the threshold current. These findings serve to guide more detailed parametric studies to produce timely results for engineering design.
Collapse
Affiliation(s)
- Emad Alkhazraji
- Integrated Photonics Lab, King Abdullah University of Science and Technology, Thuwal, 23955, Saudi Arabia
| | - Weng W Chow
- Sandia National Laboratories, Albuquerque, NM, 87185-1086, USA.
| | - Frédéric Grillot
- LTCI, Télécom Paris, Institut Polytechnique de Paris, 91120, Palaiseau, France
| | - John E Bowers
- Department of Electronic and Computer Engineering, University of California - Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Yating Wan
- Integrated Photonics Lab, King Abdullah University of Science and Technology, Thuwal, 23955, Saudi Arabia.
| |
Collapse
|
10
|
Sakaguchi J, Awaji Y, Furukawa H. Ultra-long-distance distribution of low-phase-noise reference lightwave for optical communications. OPTICS EXPRESS 2023; 31:20715-20729. [PMID: 37381188 DOI: 10.1364/oe.492367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 05/28/2023] [Indexed: 06/30/2023]
Abstract
The remote delivery of optical reference with highly stable oscillation frequency and carrier phase can eliminate the need of digital signal processing for the estimation of these parameters in optical communication. The distribution distance of the optical reference has been limited, however. In this paper, an optical reference distribution over 12,600 km is achieved while maintaining low-noise characteristics, using an ultra-narrow-linewidth laser as a reference source and a fiber Bragg grating filter for noise removal. The distributed optical reference enables 10 GBaud, 5 wavelength-division-multiplexed dual-polarization 64QAM data transmission without using carrier phase estimation, which significantly reduces off-line signal processing time. In the future, this method can enable all coherent optical signals in the network to be synchronized to a common reference ideally, thereby improving overall energy efficiency and cost.
Collapse
|
11
|
Shitikov AE, Galiev RR, Min'kov KN, Kondratiev NM, Cordette SJ, Lobanov VE, Bilenko IA. Red narrow-linewidth lasing and frequency comb from gain-switched self-injection-locked Fabry-Pérot laser diode. Sci Rep 2023; 13:9830. [PMID: 37330585 DOI: 10.1038/s41598-023-36229-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 05/31/2023] [Indexed: 06/19/2023] Open
Abstract
Narrow-linewidth lasers are in extensive demand for numerous cutting-edge applications. Such lasers operating at the visible range are of particular interest. Self-injection locking of a laser diode frequency to a high-Q whispering gallery mode is an effective and universal way to achieve superior laser performance. We demonstrate ultranarrow lasing with less than 10 Hz instantaneous linewidth for 20 [Formula: see text]s averaging time at 638 nm using a Fabry-Pérot laser diode locked to a crystalline MgF[Formula: see text] microresonator. The linewidth measured with a [Formula: see text]-separation line technique that characterizes 10 ms stability is as low as 1.4 kHz. Output power exceeds 80 mW. Demonstrated results are among the best for visible-range lasers in terms of linewidth combined with solid output power. We additionally report the first demonstration of a gain-switched regime for such stabilized Fabry-Pérot laser diode showing a high-contrast visible frequency comb generation. Tunable linespacing from 10 MHz to 3.8 GHz is observed. We demonstrated that the beatnote between the lines has sub-Hz linewidth and experiences spectral purification in the self-injection locking regime. This result might be of special importance for spectroscopy in the visible range.
Collapse
Affiliation(s)
| | - Ramzil R Galiev
- Directed Energy Research Centre, Technology Innovation Institute, Abu Dhabi, United Arab Emirates
| | | | - Nikita M Kondratiev
- Directed Energy Research Centre, Technology Innovation Institute, Abu Dhabi, United Arab Emirates
| | - Steevy J Cordette
- Directed Energy Research Centre, Technology Innovation Institute, Abu Dhabi, United Arab Emirates
| | | | - Igor A Bilenko
- Russian Quantum Center, Skolkovo, Moscow, 143025, Russia
- Faculty of Physics, Lomonosov Moscow State University, Moscow, 119991, Russia
| |
Collapse
|
12
|
Chen T, Kang Z, Yang Y, Zhao S, Zhang J, Zhang L, Wang K. Geometrical optical analysis of a gradient refractive index microresonator. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2023; 40:1208-1214. [PMID: 37706774 DOI: 10.1364/josaa.484595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 05/03/2023] [Indexed: 09/15/2023]
Abstract
Optical microresonators confine light to small volumes through resonant circulation. Herein, whispering gallery mode (WGM) microresonators have high Q factors among these microresonators, which have significant research value in the fields of fundamental physics research and optoelectronic devices. However, maintaining a very high surface finish on the side of the microresonator is necessary, as is keeping a coupling distance of tens of nanometers between the microresonator and the coupling waveguide. Thus, this makes the fabrication, coupling, and packaging of the microresonator very difficult and seriously hinders the practical application of the microresonator. In this study, the concept of gradient refractive index (GRIN) microresonator is proposed, and the radial GRIN is introduced to change the light direction and form a closed optical path within the microresonator. Herein, the mode field position of the GRIN microresonator is derived from the light transmission equation, and the theoretical result is proved by finite difference time domain (FDTD) simulation. Hence, there are several advantages to using this novel optical microresonator, including its high Q factor, strong coupling stability, and ease of integration.
Collapse
|
13
|
Li B, Wang W, Yang H, Liu H, Chu ST, Little B, Song Y, Guan B, Zhang W, Li M. Hybrid integrated narrow-linewidth semiconductor lasers. APPLIED OPTICS 2023; 62:3772-3777. [PMID: 37706995 DOI: 10.1364/ao.486492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 04/20/2023] [Indexed: 09/15/2023]
Abstract
Integrated narrow-linewidth lasers are the key devices in compact coherent optical systems of metrology, sensing, and optical microwave generation. Here, we demonstrate a hybrid integrated laser based on an optical negative feedback scheme. The laser is composed of a commercial distributed feedback (DFB) laser diode and an on-chip micro-resonator with a Q-factor of 0.815 million. The feedback optical field is coupled back to the laser cavity through the back facet. Therefore, the laser can maintain the lasing efficiency of the DFB laser diode. The linewidth of the DFB laser diode is compressed from 2 MHz to 6 kHz, corresponding to the linewidth reduction factor of 25.2 dB. The theoretical result shows that the laser performance still has a huge improvement margin through precise control of the detuning between laser frequency and the micro-resonator, as well as the phase delay of the feedback optical field. The hybrid narrow-linewidth laser diode has wide application prospects in coherent optical systems benefitting from the low cost and volume productivity.
Collapse
|
14
|
Shi L, Luo J, Jiang L, Bai M, Huang D, Li J, Chai J, Guo N, Zhu T. Narrow linewidth semiconductor multi-wavelength DFB laser array simultaneously self-injection locked to a single microring resonator. OPTICS LETTERS 2023; 48:1974-1977. [PMID: 37058620 DOI: 10.1364/ol.481618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 02/15/2023] [Indexed: 06/19/2023]
Abstract
We experimentally demonstrate a narrow linewidth semiconductor multi-wavelength distributed feedback (DFB) laser array by simultaneously injection locking each laser to the corresponding resonance of a single on-chip microring resonator. The white frequency noises of all the DFB lasers is reduced by more than 40 dB once they are simultaneously injection locked to a single microring resonator with a quality factor (Q-factor) of 2.38 million. Correspondingly, the instantaneous linewidths of all the DFB lasers are narrowed by a factor of 104. In addition, frequency combs originating from non-degenerate four-wave mixing (FWM) between the locked DFB lasers are also observed. Simultaneously injection locking multi-wavelength lasers to a single on-chip resonator may enable the possibilities of integrating a narrow-linewidth semiconductor laser array on a single chip and having multiple microcombs in a single resonator, which are in high demand in wavelength division multiplexing coherent optical communication systems and metrological applications.
Collapse
|
15
|
Kelleher ML, McLemore CA, Lee D, Davila-Rodriguez J, Diddams SA, Quinlan F. Compact, portable, thermal-noise-limited optical cavity with low acceleration sensitivity. OPTICS EXPRESS 2023; 31:11954-11965. [PMID: 37155818 DOI: 10.1364/oe.486087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We develop and demonstrate a compact (less than 6 mL) portable Fabry-Pérot optical reference cavity. A laser locked to the cavity is thermal noise limited at 2 × 10-14 fractional frequency stability. Broadband feedback control with an electro-optic modulator enables near thermal-noise-limited phase noise performance from 1 Hz to 10 kHz offset frequencies. The additional low vibration, temperature, and holding force sensitivity of our design makes it well suited for out-of-the-lab applications such as optically derived low noise microwave generation, compact and mobile optical atomic clocks, and environmental sensing through deployed fiber networks.
Collapse
|
16
|
Huang T, Ma Y, Fang Z, Zhou J, Zhou Y, Wang Z, Liu J, Wang Z, Zhang H, Wang M, Xu J, Cheng Y. Wavelength-Tunable Narrow-Linewidth Laser Diode Based on Self-Injection Locking with a High-Q Lithium Niobate Microring Resonator. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:948. [PMID: 36903826 PMCID: PMC10005327 DOI: 10.3390/nano13050948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/24/2023] [Accepted: 03/04/2023] [Indexed: 06/18/2023]
Abstract
We demonstrate a narrow linewidth 980 nm laser by self-injection locking of an electrically pumped distributed-feedback (DFB) laser diode to a high quality (Q) factor (>105) lithium niobate (LN) microring resonator. The lithium niobate microring resonator is fabricated by photolithography-assisted chemo-mechanical etching (PLACE) technique, and the Q factor of lithium niobate microring is measured as high as 6.91 × 105. The linewidth of the multimode 980 nm laser diode, which is ~2 nm measured from its output end, is narrowed down to 35 pm with a single-mode characteristic after coupling with the high-Q LN microring resonator. The output power of the narrow-linewidth microlaser is about 4.27 mW, and the wavelength tuning range reaches 2.57 nm. This work explores a hybrid integrated narrow linewidth 980 nm laser that has potential applications in high-efficient pump laser, optical tweezers, quantum information, as well as chip-based precision spectroscopy and metrology.
Collapse
Affiliation(s)
- Ting Huang
- The Extreme Optoelectromechanics Laboratory (XXL), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
| | - Yu Ma
- State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-Intense Laser Science, Shanghai Institute of Optics and Fine Mechanics (SIOM), Chinese Academy of Sciences (CAS), Shanghai 201800, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhiwei Fang
- The Extreme Optoelectromechanics Laboratory (XXL), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
- Hefei National Laboratory, Hefei 230088, China
| | - Junxia Zhou
- The Extreme Optoelectromechanics Laboratory (XXL), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Yuan Zhou
- State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-Intense Laser Science, Shanghai Institute of Optics and Fine Mechanics (SIOM), Chinese Academy of Sciences (CAS), Shanghai 201800, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhe Wang
- The Extreme Optoelectromechanics Laboratory (XXL), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
| | - Jian Liu
- The Extreme Optoelectromechanics Laboratory (XXL), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
| | - Zhenhua Wang
- The Extreme Optoelectromechanics Laboratory (XXL), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
| | - Haisu Zhang
- The Extreme Optoelectromechanics Laboratory (XXL), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
| | - Min Wang
- The Extreme Optoelectromechanics Laboratory (XXL), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
| | - Jian Xu
- The Extreme Optoelectromechanics Laboratory (XXL), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
- Hefei National Laboratory, Hefei 230088, China
| | - Ya Cheng
- The Extreme Optoelectromechanics Laboratory (XXL), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
- State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-Intense Laser Science, Shanghai Institute of Optics and Fine Mechanics (SIOM), Chinese Academy of Sciences (CAS), Shanghai 201800, China
- Hefei National Laboratory, Hefei 230088, China
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
- Collaborative Innovation Center of Light Manipulations and Applications, Shandong Normal University, Jinan 250358, China
| |
Collapse
|
17
|
Liang W, Liu Y. Compact sub-hertz linewidth laser enabled by self-injection lock to a sub-milliliter FP cavity. OPTICS LETTERS 2023; 48:1323-1326. [PMID: 36857279 DOI: 10.1364/ol.481552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
A narrow linewidth laser (NLL) of high frequency stability and small form factor is essential to enable applications in long-range sensing, quantum information, and atomic clocks. Various high performance NLLs have been demonstrated by Pound-Drever-Hall (PDH) lock or self-injection lock (SIL) of a seed laser to a vacuum-stabilized Fabry-Perot (FP) cavity of ultrahigh quality (Q) factor. However, they are often complicated lab setups due to the sophisticated stabilizing system and locking electronics. Here we report a compact NLL of 67-mL volume, realized by SIL of a diode laser to a miniature FP cavity of 7.7 × 108 Q and 0.5-mL volume, bypassing table-size vacuum as well as thermal and vibration isolation. We characterized the NLL with a self-delayed heterodyne system, where the Lorentzian linewidth reaches 60 mHz and the integrated linewidth is ∼80 Hz. The frequency noise performance exceeds that of commercial NLLs and recently reported hybrid-integrated NLL realized by SIL to high-Q on-chip ring resonators. Our work marks a major step toward a field-deployable NLL of superior performance using an ultrahigh-Q FP cavity.
Collapse
|
18
|
Shitikov AE, Lykov II, Benderov OV, Chermoshentsev DA, Gorelov IK, Danilin AN, Galiev RR, Kondratiev NM, Cordette SJ, Rodin AV, Masalov AV, Lobanov VE, Bilenko IA. Optimization of laser stabilization via self-injection locking to a whispering-gallery-mode microresonator: experimental study. OPTICS EXPRESS 2023; 31:313-327. [PMID: 36606969 DOI: 10.1364/oe.478009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
Self-injection locking of a diode laser to a high-quality-factor microresonator is widely used for frequency stabilization and linewidth narrowing. We constructed several microresonator-based laser sources with measured instantaneous linewidths of 1 Hz and used them for investigation and implementation of the self-injection locking effect. We studied analytically and experimentally the dependence of the stabilization coefficient on tunable parameters such as locking phase and coupling rate. It was shown that precise control of the locking phase allows fine-tuning of the generated frequency from the stabilized laser diode. We also showed that it is possible for such laser sources to realize fast continuous and linear frequency modulation by injection current tuning inside the self-injection locking regime. We conceptually demonstrate coherent frequency-modulated continuous wave LIDAR over a distance of 10 km using such a microresonator-stabilized laser diode in the frequency-chirping regime and measure velocities as low as sub-micrometer per second in the unmodulated case. These results could be of interest to cutting-edge technology applications such as space debris monitoring and long-range object classification, high-resolution spectroscopy, and others.
Collapse
|
19
|
Tebeneva TS, Shitikov AE, Benderov OV, Lobanov VE, Bilenko IA, Rodin AV. Ultrahigh-Q WGM microspheres from ZBLAN for the mid-IR band. OPTICS LETTERS 2022; 47:6325-6328. [PMID: 36538429 DOI: 10.1364/ol.475259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 11/02/2022] [Indexed: 06/17/2023]
Abstract
The advantages of high-quality-factor (high-Q) whispering gallery mode (WGM) microresonators can be applied to develop novel photonic devices for the mid-infrared (mid-IR) range. ZBLAN (glass based on heavy metal fluorides) is one of the most promising materials to be used for this purpose due to low optical losses in the mid-IR. We developed an original, to the best of our knowledge, fabrication method based on melting of commercially available ZBLAN-based optical fiber to produce high-Q ZBLAN microspheres with the diameters of 250 to 350 μm. We effectively excited whispering gallery modes in these microspheres and demonstrated high quality factor both at 1.55 μm and 2.64 μm. Intrinsic quality factor at telecom wavelength was shown to be (5.4 ± 0.4) × 108 which is defined by the material losses in ZBLAN. In the mid-IR at 2.64 μm we demonstrated record quality factor in ZBLAN exceeding 108 which is comparable to the highest values of the Q-factor among all materials in the mid-IR.
Collapse
|
20
|
Mitul AF, Han M. Wavelength drift suppression of a semiconductor laser with filtered optical feedback from a fiber-optic loop using active phase-delay control. OPTICS LETTERS 2022; 47:5457-5460. [PMID: 37219243 DOI: 10.1364/ol.472278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 09/26/2022] [Indexed: 05/24/2023]
Abstract
We present a method to suppress the wavelength drift of a semiconductor laser with filtered optical feedback from a long fiber-optic loop. The laser wavelength is stabilized to the filter peak through actively controlling the phase delay of the feedback light. Steady-state analysis of the laser wavelength is performed to illustrate the method. Experimentally, the wavelength drift was reduced by 75% compared to the case without phase delay control. The active phase delay control had negligible effect on the line narrowing performance of the filtered optical feedback to the limit of the measurement resolution.
Collapse
|
21
|
Guo J, McLemore CA, Xiang C, Lee D, Wu L, Jin W, Kelleher M, Jin N, Mason D, Chang L, Feshali A, Paniccia M, Rakich PT, Vahala KJ, Diddams SA, Quinlan F, Bowers JE. Chip-based laser with 1-hertz integrated linewidth. SCIENCE ADVANCES 2022; 8:eabp9006. [PMID: 36306350 PMCID: PMC9616488 DOI: 10.1126/sciadv.abp9006] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
Lasers with hertz linewidths at time scales of seconds are critical for metrology, timekeeping, and manipulation of quantum systems. Such frequency stability relies on bulk-optic lasers and reference cavities, where increased size is leveraged to reduce noise but with the trade-off of cost, hand assembly, and limited applications. Alternatively, planar waveguide-based lasers enjoy complementary metal-oxide semiconductor scalability yet are fundamentally limited from achieving hertz linewidths by stochastic noise and thermal sensitivity. In this work, we demonstrate a laser system with a 1-s linewidth of 1.1 Hz and fractional frequency instability below 10-14 to 1 s. This low-noise performance leverages integrated lasers together with an 8-ml vacuum-gap cavity using microfabricated mirrors. All critical components are lithographically defined on planar substrates, holding potential for high-volume manufacturing. Consequently, this work provides an important advance toward compact lasers with hertz linewidths for portable optical clocks, radio frequency photonic oscillators, and related communication and navigation systems.
Collapse
Affiliation(s)
- Joel Guo
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Charles A. McLemore
- National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, 440 UCB Boulder, CO 80309, USA
| | - Chao Xiang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Dahyeon Lee
- National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, 440 UCB Boulder, CO 80309, USA
| | - Lue Wu
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA 91125, USA
| | - Warren Jin
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Megan Kelleher
- National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, 440 UCB Boulder, CO 80309, USA
| | - Naijun Jin
- Department of Applied Physics, Yale University, New Haven, CT 06520, USA
| | - David Mason
- Department of Applied Physics, Yale University, New Haven, CT 06520, USA
| | - Lin Chang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | | | | | - Peter T. Rakich
- Department of Applied Physics, Yale University, New Haven, CT 06520, USA
| | - Kerry J. Vahala
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA 91125, USA
| | - Scott A. Diddams
- National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, 440 UCB Boulder, CO 80309, USA
- Department of Electrical, Computer, and Energy Engineering, University of Colorado Boulder, 425 UCB, Boulder, CO 80309, USA
| | - Franklyn Quinlan
- National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, 440 UCB Boulder, CO 80309, USA
| | - John E. Bowers
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| |
Collapse
|
22
|
Tang L, Li L, Li J, Chen M. Hybrid integrated ultralow-linewidth and fast-chirped laser for FMCW LiDAR. OPTICS EXPRESS 2022; 30:30420-30429. [PMID: 36242146 DOI: 10.1364/oe.465858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 07/19/2022] [Indexed: 06/16/2023]
Abstract
Narrow linewidth and fast-chirped frequency are essential in frequency-modulated continuous-wave lasers. We introduce a laser that meets these requirements by coupling a distributed feedback laser with an external high-Q microring resonator, where a bulky stacked piezoelectric chip is attached to the resonator for fast tuning. The laser demonstrates an ultranarrow intrinsic linewidth of 22 Hz in the self-injection-locked state. Actuated by the bulky piezoelectric chip, the maximum triangular actuation bandwidth can reach 100 kHz. The driving voltage is filtered to avoid a resonant mechanical mode, obtaining the minimum residual linearity error at 10 kHz with a 4.2 GHz tuning range. A light detection and ranging system was set up for a proof-of-concept experiment, demonstrating a high detection precision with standard deviations of 2.7 and 4.0 cm for targets at 15 and 30 m, respectively.
Collapse
|
23
|
Zhao Z, Bai Z, Jin D, Chen X, Qi Y, Ding J, Yan B, Wang Y, Lu Z, Mildren RP. The Influence of Noise Floor on the Measurement of Laser Linewidth Using Short-Delay-Length Self-Heterodyne/Homodyne Techniques. MICROMACHINES 2022; 13:1311. [PMID: 36014233 PMCID: PMC9416656 DOI: 10.3390/mi13081311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 08/09/2022] [Accepted: 08/12/2022] [Indexed: 06/15/2023]
Abstract
Delayed self-heterodyne/homodyne measurements based on an unbalanced interferometer are the most used methods for measuring the linewidth of narrow-linewidth lasers. They typically require the service of a delay of six times (or greater) than the laser coherence time to guarantee the Lorentzian characteristics of the beat notes. Otherwise, the beat notes are displayed as a coherent envelope. The linewidth cannot be directly determined from the coherence envelope. However, measuring narrow linewidths using traditional methods introduces significant errors due to the 1/f frequency noise. Here, a short fiber-based linewidth measurement scheme was proposed, and the influence of the noise floor on the measurement of the laser linewidth using this scheme was studied theoretically and experimentally. The results showed that this solution and calibration process is capable of significantly improving the measurement accuracy of narrow linewidth.
Collapse
Affiliation(s)
- Zhongan Zhao
- Center for Advanced Laser Technology, Hebei University of Technology, Tianjin 300401, China
- Hebei Key Laboratory of Advanced Laser Technology and Equipment, Tianjin 300401, China
| | - Zhenxu Bai
- Center for Advanced Laser Technology, Hebei University of Technology, Tianjin 300401, China
- Hebei Key Laboratory of Advanced Laser Technology and Equipment, Tianjin 300401, China
| | - Duo Jin
- Center for Advanced Laser Technology, Hebei University of Technology, Tianjin 300401, China
- Hebei Key Laboratory of Advanced Laser Technology and Equipment, Tianjin 300401, China
| | - Xiaojing Chen
- Shanghai Institute for Advanced Communication and Data Science, Shanghai University, Shanghai 200444, China
| | - Yaoyao Qi
- Center for Advanced Laser Technology, Hebei University of Technology, Tianjin 300401, China
- Hebei Key Laboratory of Advanced Laser Technology and Equipment, Tianjin 300401, China
| | - Jie Ding
- Center for Advanced Laser Technology, Hebei University of Technology, Tianjin 300401, China
- Hebei Key Laboratory of Advanced Laser Technology and Equipment, Tianjin 300401, China
| | - Bingzheng Yan
- Center for Advanced Laser Technology, Hebei University of Technology, Tianjin 300401, China
- Hebei Key Laboratory of Advanced Laser Technology and Equipment, Tianjin 300401, China
| | - Yulei Wang
- Center for Advanced Laser Technology, Hebei University of Technology, Tianjin 300401, China
- Hebei Key Laboratory of Advanced Laser Technology and Equipment, Tianjin 300401, China
| | - Zhiwei Lu
- Center for Advanced Laser Technology, Hebei University of Technology, Tianjin 300401, China
- Hebei Key Laboratory of Advanced Laser Technology and Equipment, Tianjin 300401, China
| | - Richard P. Mildren
- MQ Photonics Research Centre, Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109, Australia
| |
Collapse
|
24
|
Chermoshentsev DA, Shitikov AE, Lonshakov EA, Grechko GV, Sazhina EA, Kondratiev NM, Masalov AV, Bilenko IA, Lvovsky AI, Ulanov AE. Dual-laser self-injection locking to an integrated microresonator. OPTICS EXPRESS 2022; 30:17094-17105. [PMID: 36221539 DOI: 10.1364/oe.454687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 04/20/2022] [Indexed: 06/16/2023]
Abstract
Diode laser self-injection locking (SIL) to a whispering gallery mode of a high quality factor resonator is a widely used method for laser linewidth narrowing and high-frequency noise suppression. SIL has already been used for the demonstration of ultra-low-noise photonic microwave oscillators and soliton microcomb generation and has a wide range of possible applications. Up to date, SIL was demonstrated only with a single laser. However, multi-frequency and narrow-linewidth laser sources are in high demand for modern telecommunication systems, quantum technologies, and microwave photonics. Here we experimentally demonstrate the dual-laser SIL of two multifrequency laser diodes to different modes of an integrated Si3N4 microresonator. Simultaneous spectrum collapse of both lasers, as well as linewidth narrowing and high-frequency noise suppression , as well as strong nonlinear interaction of the two fields with each other, are observed. Locking both lasers to the same mode results in a simultaneous frequency and phase stabilization and coherent addition of their outputs. Additionally, we provide a comprehensive dual-SIL theory and investigate the influence of lasers on each other caused by nonlinear effects in the microresonator.
Collapse
|
25
|
Research on Silicon-Substrate-Integrated Widely Tunable, Narrow Linewidth External Cavity Lasers. CRYSTALS 2022. [DOI: 10.3390/cryst12050674] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Widely tunable, narrow linewidth external cavity lasers on silicon substrates have many important applications, such as white-light interferometry, wavelength division multiplexing systems, coherent optical communication, and optical fiber sensor technology. Wide tuning range, high laser output power, single mode, stable spectral output, and high side-mode suppression ratio external cavity lasers have attracted much attention for their merits. In this paper, two main device-integrated structures for achieving widely tunable, narrow linewidth external cavity lasers on silicon substrates are reviewed and compared in detail, such as MRR-integrated structure and MRR-and-MZI-integrated structure of external cavity semiconductor lasers. Then, the chip-integrated structures are briefly introduced from the integration mode, such as monolithic integrated, heterogeneous integrated, and hybrid integrated. Results show that the silicon-substrate-integrated external cavity lasers are a potential way to realize a wide tuning range, high power, single mode, stable spectral output, and high side-mode suppression ratio laser output.
Collapse
|
26
|
Lan T, Cao Z, Huang L, Li Y, Li F, Jiang L, Iroegbu PI, Dang L, Gao Q, Liang L, Mei K, Fu S, Yin G, Zhu T. Ultra-narrow-linewidth DFB laser array based on dual-cavity feedback. OPTICS EXPRESS 2022; 30:14617-14628. [PMID: 35473201 DOI: 10.1364/oe.447483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 03/30/2022] [Indexed: 06/14/2023]
Abstract
Herein, we propose a structure to simultaneously compress the distributed feedback (DFB) laser array's linewidth. The proposed structure is meticulously designed to ensure single longitudinal mode operation via the interference phenomenon between the laser's primary cavity and the dual-cavity feedback. Given the weak feedback effect for each wavelength in the laser array, the proposed structure could realize the intense compression of the laser linewidths. The study results show that the side-mode suppression ratios of each DFB laser are over 40 dB, and the linewidths have been compressed from 3 MHz to ∼800 Hz. Thus, we believe the idea of an overall compression linewidth scheme in the present study can be adopted for integrated laser arrays.
Collapse
|
27
|
Platicon microcomb generation using laser self-injection locking. Nat Commun 2022; 13:1771. [PMID: 35365647 PMCID: PMC8975808 DOI: 10.1038/s41467-022-29431-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 02/25/2022] [Indexed: 11/24/2022] Open
Abstract
The past decade has witnessed major advances in the development and system-level applications of photonic integrated microcombs, that are coherent, broadband optical frequency combs with repetition rates in the millimeter-wave to terahertz domain. Most of these advances are based on harnessing of dissipative Kerr solitons (DKS) in microresonators with anomalous group velocity dispersion (GVD). However, microcombs can also be generated with normal GVD using localized structures that are referred to as dark pulses, switching waves or platicons. Compared with DKS microcombs that require specific designs and fabrication techniques for dispersion engineering, platicon microcombs can be readily built using CMOS-compatible platforms such as thin-film (i.e., thickness below 300 nm) silicon nitride with normal GVD. Here, we use laser self-injection locking to demonstrate a fully integrated platicon microcomb operating at a microwave K-band repetition rate. A distributed feedback (DFB) laser edge-coupled to a Si3N4 chip is self-injection-locked to a high-Q ( > 107) microresonator with high confinement waveguides, and directly excites platicons without sophisticated active control. We demonstrate multi-platicon states and switching, perform optical feedback phase study and characterize the phase noise of the K-band platicon repetition rate and the pump laser. Laser self-injection-locked platicons could facilitate the wide adoption of microcombs as a building block in photonic integrated circuits via commercial foundry service. ’Here the authors provide the demonstration of platicon comb generation in an integrated photonic chip using laser self-injection locking, They take advantage of platicons generation in normal GVD resonators, which significantly relaxes the material and geometry design restrictions
Collapse
|
28
|
Ji J, Wang H, Ma J, Guo J, Zhang J, Tang D, Shen D. Narrow linewidth self-injection locked fiber laser based on a crystalline resonator in add-drop configuration. OPTICS LETTERS 2022; 47:1525-1528. [PMID: 35290355 DOI: 10.1364/ol.450458] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 02/18/2022] [Indexed: 06/14/2023]
Abstract
Strong and narrow spectral feedback plays a key role in self-injection locking (SIL) single-frequency lasers, especially in the stabilization of single longitudinal mode (SLM) operation of a multi-mode laser. Here, we report on a narrow linewidth SIL fiber laser that adopts a fiber add-drop configuration composing of two tapered fibers and a high-Q MgF2 crystalline whispering-gallery-mode resonator. The feedback from the drop port could be controlled and optimized for stable SLM lasing of multi-mode fiber lasers. A stable single-frequency fiber laser with white frequency noise as low as ∼0.4 Hz2/Hz, corresponding to an instantaneous linewidth of ∼1.26 Hz, is demonstrated. Compact, controllable, and all-fiber configuration in this work to achieve an ultra-narrow linewidth laser will attract interest in many applications.
Collapse
|
29
|
Coherent phase transfer for real-world twin-field quantum key distribution. Nat Commun 2022; 13:157. [PMID: 35013290 PMCID: PMC8748954 DOI: 10.1038/s41467-021-27808-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 11/30/2021] [Indexed: 11/09/2022] Open
Abstract
Quantum mechanics allows distribution of intrinsically secure encryption keys by optical means. Twin-field quantum key distribution is one of the most promising techniques for its implementation on long-distance fiber networks, but requires stabilizing the optical length of the communication channels between parties. In proof-of-principle experiments based on spooled fibers, this was achieved by interleaving the quantum communication with periodical stabilization frames. In this approach, longer duty cycles for the key streaming come at the cost of a looser control of channel length, and a successful key-transfer using this technique in real world remains a significant challenge. Using interferometry techniques derived from frequency metrology, we develop a solution for the simultaneous key streaming and channel length control, and demonstrate it on a 206 km field-deployed fiber with 65 dB loss. Our technique reduces the quantum-bit-error-rate contributed by channel length variations to <1%, representing an effective solution for real-world quantum communications.
Collapse
|
30
|
Jiang L, Shi L, Luo J, Gao Q, Bai M, Lan T, Iroegbu PI, Dang L, Huang L, Zhu T. Simultaneous self-injection locking of two VCSELs to a single whispering-gallery-mode microcavity. OPTICS EXPRESS 2021; 29:37845-37851. [PMID: 34808849 DOI: 10.1364/oe.441595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
Simultaneous self-injection locking of two vertical-cavity surface-emitting lasers (VCSELs) to a single whispering-gallery-mode (WGM) microcavity is experimentally demonstrated. The linewidths of the two VCSELs are compressed from 3.5 MHz and 5 MHz to 20.9 kHz and 24.1 kHz, which is on the same order of magnitude as that of locking each VCSEL to the microcavity separately. Moreover, the frequency noises of the two simultaneously locked VCSELs are suppressed by more than 60 dB below the offset frequency of 100 kHz compared to that of the free-running VCSELs. The method demonstrated here might be used in the multi-wavelength laser array with low phase and frequency noises, especially the VCSELs with the unique architecture of a two-dimensional array.
Collapse
|
31
|
Zhu X, Li X, Zhang R, Zhao Z, Kong M. Using DFB laser self-injection locked to an optical waveguide ring resonator as a light source of Φ-OTDR. APPLIED OPTICS 2021; 60:9769-9773. [PMID: 34807162 DOI: 10.1364/ao.438572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/02/2021] [Indexed: 06/13/2023]
Abstract
A distributed feedback (DFB) semiconductor laser self-injection locked to an optical waveguide ring resonator (OWRR) is used in a phase-sensitive optical time-domain reflectometry (Φ-OTDR) vibration sensing system as its light source. A frequency-hopping-free period of more than 100 s is realized. A spatial resolution of 13 m at 4700 m and simultaneous measurement of two vibration sources are realized. The measurable vibration frequency is from 8 Hz to the upper limit of the sampling theorem. These satisfactory performances demonstrate that the DFB laser locked to an OWRR is not only cost effective, but also stable and reliable for Φ-OTDR sensing.
Collapse
|
32
|
Li B, Jin W, Wu L, Chang L, Wang H, Shen B, Yuan Z, Feshali A, Paniccia M, Vahala KJ, Bowers JE. Reaching fiber-laser coherence in integrated photonics. OPTICS LETTERS 2021; 46:5201-5204. [PMID: 34653151 DOI: 10.1364/ol.439720] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 09/26/2021] [Indexed: 06/13/2023]
Abstract
We self-injection-lock a diode laser to a 1.41 m long, ultra-high Q integrated resonator. The hybrid integrated laser reaches a frequency noise floor of 0.006Hz2/Hz at 4 MHz offset, corresponding to a Lorentzian linewidth below 40 mHz-a record among semiconductor lasers. It also exhibits exceptional stability at low-offset frequencies, with frequency noise of 200Hz2/Hz at 100 Hz offset. Such performance, realized in a system comprised entirely of integrated photonic chips, marks a milestone in the development of integrated photonics; and, for the first time, to the best of our knowledge, exceeds the frequency noise performance of commercially available, high-performance fiber lasers.
Collapse
|
33
|
Kittlaus EA, Eliyahu D, Ganji S, Williams S, Matsko AB, Cooper KB, Forouhar S. A low-noise photonic heterodyne synthesizer and its application to millimeter-wave radar. Nat Commun 2021; 12:4397. [PMID: 34285213 PMCID: PMC8292534 DOI: 10.1038/s41467-021-24637-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 06/15/2021] [Indexed: 11/18/2022] Open
Abstract
Microwave photonics offers transformative capabilities for ultra-wideband electronic signal processing and frequency synthesis with record-low phase noise levels. Despite the intrinsic bandwidth of optical systems operating at ~200 THz carrier frequencies, many schemes for high-performance photonics-based microwave generation lack broadband tunability, and experience tradeoffs between noise level, complexity, and frequency. An alternative approach uses direct frequency down-mixing of two tunable semiconductor lasers on a fast photodiode. This form of optical heterodyning is frequency-agile, but experimental realizations have been hindered by the relatively high noise of free-running lasers. Here, we demonstrate a heterodyne synthesizer based on ultralow-noise self-injection-locked lasers, enabling highly-coherent, photonics-based microwave and millimeter-wave generation. Continuously-tunable operation is realized from 1-104 GHz, with constant phase noise of -109 dBc/Hz at 100 kHz offset from carrier. To explore its practical utility, we leverage this photonic source as the local oscillator within a 95-GHz frequency-modulated continuous wave (FMCW) radar. Through field testing, we observe dramatic reduction in phase-noise-related Doppler and ranging artifacts as compared to the radar’s existing electronic synthesizer. These results establish strong potential for coherent heterodyne millimeter-wave generation, opening the door to a variety of future applications including high-dynamic range remote sensing, wideband wireless communications, and THz spectroscopy. Photonics-based radars offer intriguing potential but face tradeoffs in tunability, complexity, and noise. Here the authors present microwave generation in a photonics platform by heterodyning of two low-noise, self-injection-locked lasers, and demonstrate its advantages in an FMCW radar system.
Collapse
Affiliation(s)
- Eric A Kittlaus
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA.
| | | | | | | | - Andrey B Matsko
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Ken B Cooper
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Siamak Forouhar
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| |
Collapse
|
34
|
Xiang C, Liu J, Guo J, Chang L, Wang RN, Weng W, Peters J, Xie W, Zhang Z, Riemensberger J, Selvidge J, Kippenberg TJ, Bowers JE. Laser soliton microcombs heterogeneously integrated on silicon. Science 2021; 373:99-103. [PMID: 34210884 DOI: 10.1126/science.abh2076] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 05/20/2021] [Indexed: 12/22/2022]
Abstract
Silicon photonics enables wafer-scale integration of optical functionalities on chip. Silicon-based laser frequency combs can provide integrated sources of mutually coherent laser lines for terabit-per-second transceivers, parallel coherent light detection and ranging, or photonics-assisted signal processing. We report heterogeneously integrated laser soliton microcombs combining both indium phospide/silicon (InP/Si) semiconductor lasers and ultralow-loss silicon nitride (Si3N4) microresonators on a monolithic silicon substrate. Thousands of devices can be produced from a single wafer by using complementary metal-oxide-semiconductor-compatible techniques. With on-chip electrical control of the laser-microresonator relative optical phase, these devices can output single-soliton microcombs with a 100-gigahertz repetition rate. Furthermore, we observe laser frequency noise reduction due to self-injection locking of the InP/Si laser to the Si3N4 microresonator. Our approach provides a route for large-volume, low-cost manufacturing of narrow-linewidth, chip-based frequency combs for next-generation high-capacity transceivers, data centers, space and mobile platforms.
Collapse
Affiliation(s)
- Chao Xiang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Junqiu Liu
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Joel Guo
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Lin Chang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Rui Ning Wang
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Wenle Weng
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Jonathan Peters
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Weiqiang Xie
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Zeyu Zhang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Johann Riemensberger
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Jennifer Selvidge
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Tobias J Kippenberg
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
| | - John E Bowers
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA. .,Materials Department, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| |
Collapse
|
35
|
Jiang L, Shi L, Luo J, Gao Q, Lan T, Huang L, Zhu T. Narrow linewidth VCSEL based on resonant optical feedback from an on-chip microring add-drop filter. OPTICS LETTERS 2021; 46:2320-2323. [PMID: 33988573 DOI: 10.1364/ol.424496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 04/13/2021] [Indexed: 06/12/2023]
Abstract
We demonstrate a narrow linewidth vertical-cavity surface-emitting laser (VCSEL) by injecting resonant optical feedback into the lasing cavity. A single longitudinal mode VCSEL with a Lorentzian linewidth of 32.6 kHz and a purified optical spectrum is experimentally achieved by an on-chip microring add-drop filter with a quality factor of 1.36 million, where the feedback level is ${-}{47.77}\;{\rm{dB}}$. The frequency noise spectrum of the VCSEL demonstrates that the thermo-optic effect in the microring resonator can also stabilize the lasing frequency. A VCSEL with narrow linewidth and stable frequency provides a high-performance light source for a single VCSEL or VCSEL array-based application.
Collapse
|
36
|
Hao L, Wang X, Guo D, Jia K, Fan P, Guo J, Ni X, Zhao G, Xie Z, Zhu SN. Narrow-linewidth self-injection locked diode laser with a high-Q fiber Fabry-Perot resonator. OPTICS LETTERS 2021; 46:1397-1400. [PMID: 33720196 DOI: 10.1364/ol.415859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 02/08/2021] [Indexed: 06/12/2023]
Abstract
Narrow-linewidth lasers are essential for various applications, but are limited by their size, weight, power, and cost requirements. Here we demonstrate a self-injection locked diode laser fabricated with a high quality factor fiber Fabry-Perot resonator, with a 145 Hz free-running linewidth. The locking scheme is all-fiber for plug-and-play operation. White frequency noise of 50Hz2/Hz is measured with over 42 dB reduction from the low-cost TO-can distributed feedback laser diode, and shows its wide applications in a compact and cost-effective way.
Collapse
|
37
|
Voloshin AS, Kondratiev NM, Lihachev GV, Liu J, Lobanov VE, Dmitriev NY, Weng W, Kippenberg TJ, Bilenko IA. Dynamics of soliton self-injection locking in optical microresonators. Nat Commun 2021; 12:235. [PMID: 33431830 PMCID: PMC7801488 DOI: 10.1038/s41467-020-20196-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 10/30/2020] [Indexed: 11/08/2022] Open
Abstract
Soliton microcombs constitute chip-scale optical frequency combs, and have the potential to impact a myriad of applications from frequency synthesis and telecommunications to astronomy. The demonstration of soliton formation via self-injection locking of the pump laser to the microresonator has significantly relaxed the requirement on the external driving lasers. Yet to date, the nonlinear dynamics of this process has not been fully understood. Here, we develop an original theoretical model of the laser self-injection locking to a nonlinear microresonator, i.e., nonlinear self-injection locking, and construct state-of-the-art hybrid integrated soliton microcombs with electronically detectable repetition rate of 30 GHz and 35 GHz, consisting of a DFB laser butt-coupled to a silicon nitride microresonator chip. We reveal that the microresonator's Kerr nonlinearity significantly modifies the laser diode behavior and the locking dynamics, forcing laser emission frequency to be red-detuned. A novel technique to study the soliton formation dynamics as well as the repetition rate evolution in real-time uncover non-trivial features of the soliton self-injection locking, including soliton generation at both directions of the diode current sweep. Our findings provide the guidelines to build electrically driven integrated microcomb devices that employ full control of the rich dynamics of laser self-injection locking, key for future deployment of microcombs for system applications.
Collapse
Affiliation(s)
- Andrey S Voloshin
- Russian Quantum Center, Moscow, 143026, Russia
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | | | - Grigory V Lihachev
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Junqiu Liu
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Valery E Lobanov
- Russian Quantum Center, Moscow, 143026, Russia
- National University of Science and Technology (MISiS), 119049, Moscow, Russia
| | - Nikita Yu Dmitriev
- Russian Quantum Center, Moscow, 143026, Russia
- Moscow Institute of Physics and Technology (MIPT), Dolgoprudny, Moscow Region, 141701, Russia
| | - Wenle Weng
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Tobias J Kippenberg
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015, Lausanne, Switzerland.
| | - Igor A Bilenko
- Russian Quantum Center, Moscow, 143026, Russia.
- Faculty of Physics, M.V. Lomonosov Moscow State University, 119991, Moscow, Russia.
| |
Collapse
|
38
|
Kondratiev NM, Lobanov VE, Lonshakov EA, Dmitriev NY, Voloshin AS, Bilenko IA. Numerical study of solitonic pulse generation in the self-injection locking regime at normal and anomalous group velocity dispersion. OPTICS EXPRESS 2020; 28:38892-38906. [PMID: 33379448 DOI: 10.1364/oe.411544] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 11/19/2020] [Indexed: 06/12/2023]
Abstract
We developed an original model describing the process of the frequency comb generation in the self-injection locking regime and performed numerical simulation of this process. Generation of the dissipative Kerr solitons in the self-injection locking regime at anomalous group velocity dispersion was studied numerically. Different regimes of the soliton excitation depending on the locking phase, backscattering parameter and pump power were identified. It was also proposed and confirmed numerically that self-injection locking may provide an easy way for the generation of the frequency combs at normal group velocity dispersion. Generation of platicons was demonstrated and studied in detail. The parameter range providing platicon excitation was found.
Collapse
|
39
|
Loh W, Stuart J, Reens D, Bruzewicz CD, Braje D, Chiaverini J, Juodawlkis PW, Sage JM, McConnell R. Operation of an optical atomic clock with a Brillouin laser subsystem. Nature 2020; 588:244-249. [PMID: 33299197 DOI: 10.1038/s41586-020-2981-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 10/01/2020] [Indexed: 11/09/2022]
Abstract
Microwave atomic clocks have traditionally served as the 'gold standard' for precision measurements of time and frequency. However, over the past decade, optical atomic clocks1-6 have surpassed the precision of their microwave counterparts by two orders of magnitude or more. Extant optical clocks occupy volumes of more than one cubic metre, and it is a substantial challenge to enable these clocks to operate in field environments, which requires the ruggedization and miniaturization of the atomic reference and clock laser along with their supporting lasers and electronics4,7,8,9. In terms of the clock laser, prior laboratory demonstrations of optical clocks have relied on the exceptional performance gained through stabilization using bulk cavities, which unfortunately necessitates the use of vacuum and also renders the laser susceptible to vibration-induced noise. Here, using a stimulated Brillouin scattering laser subsystem that has a reduced cavity volume and operates without vacuum, we demonstrate a promising component of a portable optical atomic clock architecture. We interrogate a 88Sr+ ion with our stimulated Brillouin scattering laser and achieve a clock exhibiting short-term stability of 3.9 × 10-14 over one second-an improvement of an order of magnitude over state-of-the-art microwave clocks. This performance increase within a potentially portable system presents a compelling avenue for substantially improving existing technology, such as the global positioning system, and also for enabling the exploration of topics such as geodetic measurements of the Earth, searches for dark matter and investigations into possible long-term variations of fundamental physics constants10-12.
Collapse
Affiliation(s)
- William Loh
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, MA, USA.
| | - Jules Stuart
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, MA, USA.,Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - David Reens
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, MA, USA
| | - Colin D Bruzewicz
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, MA, USA
| | - Danielle Braje
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, MA, USA
| | - John Chiaverini
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, MA, USA
| | - Paul W Juodawlkis
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, MA, USA
| | - Jeremy M Sage
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, MA, USA.,Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Robert McConnell
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, MA, USA
| |
Collapse
|
40
|
Spirin VV, Bueno Escobedo JL, Korobko DA, Mégret P, Fotiadi AA. Dual-frequency laser comprising a single fiber ring cavity for self-injection locking of DFB laser diode and Brillouin lasing. OPTICS EXPRESS 2020; 28:37322-37333. [PMID: 33379569 DOI: 10.1364/oe.406040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 11/04/2020] [Indexed: 06/12/2023]
Abstract
Low-noise lasers are a powerful tool in precision spectroscopy, displacement measurements, and development of advanced optical atomic clocks. While all applications benefit from lower frequency noise and robust design, some of them also require lasing at two frequencies. Here, we introduce a simple dual-frequency laser leveraging a ring fiber cavity exploited both for self-injection locking of a standard semiconductor distributed feedback (DFB) laser and for generation of Stokes light via stimulated Brillouin scattering. In contrast to the previous laser configurations, the system is supplied by a low-bandwidth active optoelectronic feedback. Importantly, continuous operation of two mutually locked frequencies is provided by self-injection locking, while the active feedback loop is used just to support this regime. The fiber configuration reduces the natural Lorentzian linewidth of light emitted by the laser at pump and Stokes frequencies down to 270 Hz and 110 Hz, respectively, and features a stable 300-Hz-width RF spectrum recorded with beating of two laser outputs. Translating the proposed laser design to integrated photonics will dramatically reduce cost and footprint for many laser applications such as ultra-high capacity fiber and data center networks, atomic clocks, and microwave photonics.
Collapse
|
41
|
Lobanov VE, Shitikov AE, Galiev RR, Min'kov KN, Kondratiev NM. Generation and properties of dissipative Kerr solitons and platicons in optical microresonators with backscattering. OPTICS EXPRESS 2020; 28:36544-36558. [PMID: 33379746 DOI: 10.1364/oe.410318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 10/30/2020] [Indexed: 06/12/2023]
Abstract
Generation and properties of dissipative Kerr solitons and platicons in optical microresonators are studied in the presence of the backscattering using the original analytical model considering a linear forward-backward waves coupling and nonlinear cross-action. We reveal that the backscattering may suppress the generation of the solitonic pulses or destabilize them for both anomalous and normal group velocity dispersion. We also demonstrate the possibility of switching between different soliton states. The influence of the linear and nonlinear coupling is analysed. It is shown that while the impact of the nonlinear coupling on the generation of the bright solitons is rather weak, it is significantly more pronounced for the platicon excitation process.
Collapse
|
42
|
Geng J, Yang L, Zhao S, Zhang Y. Resonant micro-optical gyro based on self-injection locking. OPTICS EXPRESS 2020; 28:32907-32915. [PMID: 33114965 DOI: 10.1364/oe.405974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 10/08/2020] [Indexed: 06/11/2023]
Abstract
We propose the idea and design of a novel resonant micro-optical gyro based on a self-injection locking technique. By enhancing the reciprocity and measuring beat frequency, the sensitivity of gyro is improved effectively, which is usually limited by two main factors: low signal-to-noise ratio and immature signal detecting technique. In addition, a small size distributed feedback semiconductor laser with megahertz linewidth is used for miniaturization, instead of the narrow linewidth and tunable laser in traditional resonant gyros. Sensitivity of this resonant micro-optical gyro depends, in fact, on the accuracy of time measurement. In this paper, theory sensitivity is demonstrated to be at the order of 10-4 deg/h under a 6 KHz modulation frequency.
Collapse
|
43
|
Zhang H, Cohen DA, Chan P, Wong MS, Li P, Li H, Nakamura S, Denbaars SP. High performance of a semipolar InGaN laser with a phase-shifted embedded hydrogen silsesquioxane (HSQ) grating. OPTICS LETTERS 2020; 45:5844-5847. [PMID: 33057299 DOI: 10.1364/ol.403679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 09/01/2020] [Indexed: 06/11/2023]
Abstract
Single-frequency blue laser sources are of interest for an increasing number of emerging applications but are still difficult to implement and expensive to fabricate and suffer from poor robustness. Here a novel and universal grating design to realize distributed optical feedback in visible semiconductor laser diodes (LDs) was demonstrated on a semipolar InGaN LD, and its unique effect on the laser performance was investigated. For the first time, to the best of our knowledge, a low threshold voltage, record-high power output, and ultra-narrow single-mode lasing were simultaneously obtained on the new laser structure with a thinner p-GaN layer and a third-order phase-shifted embedded dielectric grating. Under continuous-wave operation, such 450 nm lasers achieved 35 dB side-mode suppression ratio, less than 2 pm FWHM, and near 400 mW total output power at room temperature.
Collapse
|
44
|
Application of a self-injection locked cyan laser for Barium ion cooling and spectroscopy. Sci Rep 2020; 10:16494. [PMID: 33020525 PMCID: PMC7536389 DOI: 10.1038/s41598-020-73373-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Accepted: 08/25/2020] [Indexed: 11/26/2022] Open
Abstract
Compact, high power lasers with narrow linewidth are important tools for the manipulation of quantum systems. We demonstrate a compact, self-injection locked, Fabry-Perot semiconductor laser diode with high output power at 493 nm. A high quality factor magnesium fluoride whispering gallery mode resonator enables both high passive stability and 1 kHz instantaneous linewidth. We use this laser for laser-cooling, in-situ isotope purifcation, and probing barium atomic ions confined in a radio-frequency ion trap. The results here demonstrate the suitability of these lasers in trapped ion quantum information processing and for probing weak coherent optical transitions.
Collapse
|
45
|
Stern L, Zhang W, Chang L, Guo J, Xiang C, Tran MA, Huang D, Peters JD, Kinghorn D, Bowers JE, Papp SB. Ultra-precise optical-frequency stabilization with heterogeneous III-V/Si lasers. OPTICS LETTERS 2020; 45:5275-5278. [PMID: 32932510 DOI: 10.1364/ol.398845] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 07/02/2020] [Indexed: 06/11/2023]
Abstract
The demand for low-noise, continuous-wave, frequency-tunable lasers based on semiconductor integrated photonics has advanced in support of numerous applications. In particular, an important goal is to achieve a narrow spectral linewidth, commensurate with bulk-optic or fiber-optic laser platforms. Here we report on laser-frequency-stabilization experiments with a heterogeneously integrated III/V-Si widely tunable laser and a high-finesse, thermal-noise-limited photonic resonator. This hybrid architecture offers a chip-scale optical-frequency reference with an integrated linewidth of 60 Hz and a fractional frequency stability of 2.5×10-13 at 1 s integration time. We explore the potential for stabilization with respect to a resonator with lower thermal noise by characterizing laser-noise contributions such as residual amplitude modulation and photodetection noise. Widely tunable, compact and integrated, cost-effective, stable, and narrow-linewidth lasers are envisioned for use in various fields, including communication, spectroscopy, and metrology.
Collapse
|
46
|
Ying K, Liang H, Chen D, Sun Y, Pi H, Wei F, Yang F, Cai H. Ultralow noise DFB fiber laser with self-feedback mechanics utilizing the inherent photothermal effect. OPTICS EXPRESS 2020; 28:23717-23727. [PMID: 32752364 DOI: 10.1364/oe.400083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 07/20/2020] [Indexed: 06/11/2023]
Abstract
Single frequency laser sources with low frequency noise are now at the heart of precision high-end science, from the most precise optical atomic clocks to gravitational-wave detection, thanks to the rapid development of laser frequency stabilization techniques based on optical or electrical feedback from an external reference cavity. Despite the tremendous progress, these laser systems are relatively high in terms of complexity and cost, essentially suitable for the laboratory environment. Nevertheless, more and more commercial applications also demand laser sources with low noise to upgrade their performance, such as fiber optic sensing and LiDAR, which require reduced complexity and good robustness to environmental perturbations. Here, we describe an ultralow noise DFB fiber laser with self-feedback mechanics that utilizes the inherent photothermal effect through the regulation of the thermal expansion coefficient of laser cavity. Over 20 dB of frequency noise reduction below several tens of kilohertz Fourier frequency is achieved, limited by the fundamental thermal noise, which is, to date, one of the best results for a free-running DFB fiber laser. The outcome of this work offers promising prospects for versatile applications due to its ultralow frequency noise, simplicity, low cost, and environmental robustness.
Collapse
|
47
|
Wang Z, Ke C, Zhong Y, Xing C, Wang H, Yang K, Cui S, Liu D. Ultra-narrow-linewidth measurement utilizing dual-parameter acquisition through a partially coherent light interference. OPTICS EXPRESS 2020; 28:8484-8493. [PMID: 32225473 DOI: 10.1364/oe.387398] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 02/27/2020] [Indexed: 06/10/2023]
Abstract
Laser linewidths of the order of 100 Hz are challenging to measure with existing technology. We propose a simple, efficient method to measure ultra-narrow linewidths using dual-parameter acquisition based on partially coherent light interference. The linewidth is obtained using two parameters that are easily extracted from the power spectrum. This method reduces the influence of 1/f noise by utilizing a kilometer-order-length delay fiber and is independent of the fiber-length error for a general situation. Simulation results show that, for a length error less than 10%, the total linewidth measurement error is less than 0.3%. Experimental results confirm the feasibility and superior performance of this method.
Collapse
|
48
|
Zhang L, Chen L, Bao X. Unveiling delay-time-resolved phase noise statistics of narrow-linewidth laser via coherent optical time domain reflectometry. OPTICS EXPRESS 2020; 28:6719-6733. [PMID: 32225913 DOI: 10.1364/oe.387185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 02/13/2020] [Indexed: 06/10/2023]
Abstract
Laser with high spectral purity plays a crucial role in high-precision optical metrology and coherent communication. Thanks to the rapid development of laser frequency stabilization, the laser phase noise can be remarkably compensated, allowing its ultra-narrow linewidth subject to mostly quantum limit. Nevertheless, the accurate characterization of phase noise statistics and its linewidth of a highly coherent laser remains ambiguous and challenging. Here, we present an approach capable of revealing delay-time-resolved phase noise statistics of a coherent laser based on coherent optical time domain reflectometry (COTDR), in which distributed Rayleigh scattering along a delay fiber essentially allows a time-of-flight mapping of a heterodyne beating signal associated with delay-time-dependent phase information from a single laser source. Ultimately, this novel technique facilitates precise measurement of ultra-narrow laser linewidth by exploiting its delay-time-resolved phase jitter statistics of random fiber laser with pump lasers of various linewidths, confirmed with the analytical modeling and numerical simulations.
Collapse
|
49
|
Lucas E, Brochard P, Bouchand R, Schilt S, Südmeyer T, Kippenberg TJ. Ultralow-noise photonic microwave synthesis using a soliton microcomb-based transfer oscillator. Nat Commun 2020; 11:374. [PMID: 31953397 PMCID: PMC6969110 DOI: 10.1038/s41467-019-14059-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 11/25/2019] [Indexed: 11/09/2022] Open
Abstract
The synthesis of ultralow-noise microwaves is of both scientific and technological relevance for timing, metrology, communications and radio-astronomy. Today, the lowest reported phase noise signals are obtained via optical frequency-division using mode-locked laser frequency combs. Nonetheless, this technique ideally requires high repetition rates and tight comb stabilisation. Here, a microresonator-based Kerr frequency comb (soliton microcomb) with a 14 GHz repetition rate is generated with an ultra-stable pump laser and used to derive an ultralow-noise microwave reference signal, with an absolute phase noise level below -60 dBc/Hz at 1 Hz offset frequency and -135 dBc/Hz at 10 kHz. This is achieved using a transfer oscillator approach, where the free-running microcomb noise (which is carefully studied and minimised) is cancelled via a combination of electronic division and mixing. Although this proof-of-principle uses an auxiliary comb for detecting the microcomb's offset frequency, we highlight the prospects of this method with future self-referenced integrated microcombs and electro-optic combs, that would allow for ultralow-noise microwave and sub-terahertz signal generators.
Collapse
Affiliation(s)
- Erwan Lucas
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Pierre Brochard
- Laboratoire Temps-Fréquence, Université de Neuchâtel, CH-2000, Neuchâtel, Switzerland
| | - Romain Bouchand
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Stéphane Schilt
- Laboratoire Temps-Fréquence, Université de Neuchâtel, CH-2000, Neuchâtel, Switzerland
| | - Thomas Südmeyer
- Laboratoire Temps-Fréquence, Université de Neuchâtel, CH-2000, Neuchâtel, Switzerland
| | - Tobias J Kippenberg
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland.
| |
Collapse
|
50
|
Spirin VV, Bueno Escobedo JL, Korobko DA, Mégret P, Fotiadi AA. Stabilizing DFB laser injection-locked to an external fiber-optic ring resonator. OPTICS EXPRESS 2020; 28:478-484. [PMID: 32118973 DOI: 10.1364/oe.28.000478] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 11/25/2019] [Indexed: 06/10/2023]
Abstract
Self-injection locking to an external fiber cavity is an efficient technique enabling drastic linewidth narrowing and self-stabilization of semiconductor lasers. The main drawback of this technique is its high sensitivity to fluctuations of the configuration parameters and surroundings. In the proposed laser configuration, to the best our knowledge, for the first time the self-injection locking mechanism is used in conjunction with a simple active optoelectronic feedback, ensuring stable mode-hopping free laser operation in a single longitudinal mode. Locking to 4-m length fiber resonator causes a drastic narrowing of the DFB laser linewidth down to 2.8 kHz and a reduction of the laser phase noise by three orders of magnitude. We have explored key features of the laser dynamics with and without active feedback, revealing stability and tunability of the laser linewidth as an additional benefit of the proposed technique.
Collapse
|