1
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He Y, Cheng L, Wang H, Zhang Y, Meade R, Vahala K, Zhang M, Li J. Chip-scale high-performance photonic microwave oscillator. SCIENCE ADVANCES 2024; 10:eado9570. [PMID: 39141728 PMCID: PMC11323879 DOI: 10.1126/sciadv.ado9570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 07/09/2024] [Indexed: 08/16/2024]
Abstract
Optical frequency division based on bulk or fiber optics provides unprecedented spectral purity for microwave oscillators. To extend the applications of this approach, the challenges are to develop miniaturized oscillators without trading off phase noise performance. Here, we report a chip-scale high-performance photonic microwave oscillator based on integrated electro-optical frequency division. Dual distributed-feedback lasers are co-self-injection locked to a single silicon nitride spiral resonator to provide a record-high-stability, fully on-chip optical reference. An integrated electro-optical frequency comb based on a thin-film lithium niobate phase modulator chip is leveraged to perform optical-to-microwave frequency division. The resulting integrated photonic microwave oscillator achieves a record-low phase noise for chip-scale oscillators. The results represent a major advance in high-performance, integrated photonic microwave oscillators for applications including signal processing, radar, timing, and coherent communications.
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Affiliation(s)
- Yang He
- hQphotonics Inc., 2500 E Colorado Blvd Suite 330, Pasadena CA 91107, USA
| | - Long Cheng
- hQphotonics Inc., 2500 E Colorado Blvd Suite 330, Pasadena CA 91107, USA
| | - Heming Wang
- hQphotonics Inc., 2500 E Colorado Blvd Suite 330, Pasadena CA 91107, USA
| | - Yu Zhang
- HyperLight Corporation, 1 Bow Street, Suite 420, Cambridge, MA 02138, USA
| | - Roy Meade
- HyperLight Corporation, 1 Bow Street, Suite 420, Cambridge, MA 02138, USA
| | - Kerry Vahala
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA 91125, USA
| | - Mian Zhang
- HyperLight Corporation, 1 Bow Street, Suite 420, Cambridge, MA 02138, USA
| | - Jiang Li
- hQphotonics Inc., 2500 E Colorado Blvd Suite 330, Pasadena CA 91107, USA
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2
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Guo J, Xiang C, Jin W, Peters J, Li M, Morin T, Xia Y, Bowers JE. Investigation of Q degradation in low-loss Si 3N 4 from heterogeneous laser integration. OPTICS LETTERS 2024; 49:4613-4616. [PMID: 39146118 DOI: 10.1364/ol.530161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Accepted: 07/25/2024] [Indexed: 08/17/2024]
Abstract
High-performance, high-volume-manufacturing Si3N4 photonics requires extremely low waveguide losses augmented with heterogeneously integrated lasers for applications beyond traditional markets of high-capacity interconnects. State-of-the-art quality factors (Q) over 200 million at 1550 nm have been shown previously; however, maintaining high Qs throughout laser fabrication has not been shown. Here, Si3N4 resonator intrinsic Qs over 100 million are demonstrated on a fully integrated heterogeneous laser platform. Qi is measured throughout laser processing steps, showing degradation down to 50 million from dry etching, metal evaporation, and ion implant steps, and controllable recovery to over 100 million from annealing at 250 ∘C-350 ∘C.
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3
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Cooper A, Olivieri L, Cutrona A, Das D, Peters L, Chu ST, Little B, Morandotti R, Moss DJ, Peccianti M, Pasquazi A. Parametric interaction of laser cavity-solitons with an external CW pump. OPTICS EXPRESS 2024; 32:21783-21794. [PMID: 38859524 DOI: 10.1364/oe.524838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 05/05/2024] [Indexed: 06/12/2024]
Abstract
We study the interaction of a laser cavity-soliton microcomb with an externally coupled, co-propagating tunable CW pump, observing parametric Kerr interactions which lead to the formation of both a cross-phase modulation and a four-wave mixing replica of the laser cavity-soliton. We compare and explain the dependence of the microcomb spectra from both the cavity-soliton and pump parameters, demonstrating the ability to adjust the microcomb externally without breaking or interfering with the soliton state. The parametric nature of the process agrees with numerical simulations. The parametric extended state maintains the typical robustness of laser-cavity solitons.
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4
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Kudelin I, Groman W, Ji QX, Guo J, Kelleher ML, Lee D, Nakamura T, McLemore CA, Shirmohammadi P, Hanifi S, Cheng H, Jin N, Wu L, Halladay S, Luo Y, Dai Z, Jin W, Bai J, Liu Y, Zhang W, Xiang C, Chang L, Iltchenko V, Miller O, Matsko A, Bowers SM, Rakich PT, Campbell JC, Bowers JE, Vahala KJ, Quinlan F, Diddams SA. Photonic chip-based low-noise microwave oscillator. Nature 2024; 627:534-539. [PMID: 38448599 PMCID: PMC10954552 DOI: 10.1038/s41586-024-07058-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 01/11/2024] [Indexed: 03/08/2024]
Abstract
Numerous modern technologies are reliant on the low-phase noise and exquisite timing stability of microwave signals. Substantial progress has been made in the field of microwave photonics, whereby low-noise microwave signals are generated by the down-conversion of ultrastable optical references using a frequency comb1-3. Such systems, however, are constructed with bulk or fibre optics and are difficult to further reduce in size and power consumption. In this work we address this challenge by leveraging advances in integrated photonics to demonstrate low-noise microwave generation via two-point optical frequency division4,5. Narrow-linewidth self-injection-locked integrated lasers6,7 are stabilized to a miniature Fabry-Pérot cavity8, and the frequency gap between the lasers is divided with an efficient dark soliton frequency comb9. The stabilized output of the microcomb is photodetected to produce a microwave signal at 20 GHz with phase noise of -96 dBc Hz-1 at 100 Hz offset frequency that decreases to -135 dBc Hz-1 at 10 kHz offset-values that are unprecedented for an integrated photonic system. All photonic components can be heterogeneously integrated on a single chip, providing a significant advance for the application of photonics to high-precision navigation, communication and timing systems.
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Affiliation(s)
- Igor Kudelin
- National Institute of Standards and Technology, Boulder, CO, USA.
- Department of Physics, University of Colorado Boulder, Boulder, CO, USA.
| | - William Groman
- National Institute of Standards and Technology, Boulder, CO, USA
- Department of Physics, University of Colorado Boulder, Boulder, CO, USA
| | - Qing-Xin Ji
- 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
| | - Megan L Kelleher
- National Institute of Standards and Technology, Boulder, CO, USA
- Department of Physics, University of Colorado Boulder, Boulder, CO, USA
| | - Dahyeon Lee
- National Institute of Standards and Technology, Boulder, CO, USA
- Department of Physics, University of Colorado Boulder, Boulder, CO, USA
| | - Takuma Nakamura
- National Institute of Standards and Technology, Boulder, CO, USA
- Department of Physics, University of Colorado Boulder, Boulder, CO, USA
| | - Charles A McLemore
- National Institute of Standards and Technology, Boulder, CO, USA
- Department of Physics, University of Colorado Boulder, Boulder, CO, USA
| | - Pedram Shirmohammadi
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA
| | - Samin Hanifi
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA
| | - Haotian Cheng
- Department of Applied Physics, Yale University, New Haven, CT, USA
| | - Naijun Jin
- Department of Applied Physics, Yale University, New Haven, CT, USA
| | - Lue Wu
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA, USA
| | - Samuel Halladay
- Department of Applied Physics, Yale University, New Haven, CT, USA
| | - Yizhi Luo
- Department of Applied Physics, Yale University, New Haven, CT, USA
| | - Zhaowei Dai
- Department of Applied Physics, Yale University, New Haven, CT, USA
| | - Warren Jin
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Junwu Bai
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA
| | - Yifan Liu
- National Institute of Standards and Technology, Boulder, CO, USA
- Department of Physics, University of Colorado Boulder, Boulder, CO, USA
| | - Wei Zhang
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Chao Xiang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Lin Chang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Vladimir Iltchenko
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Owen Miller
- Department of Applied Physics, Yale University, New Haven, CT, USA
| | - Andrey Matsko
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Steven M Bowers
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA
| | - Peter T Rakich
- Department of Applied Physics, Yale University, New Haven, CT, USA
| | - Joe C Campbell
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA
| | - John E Bowers
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Kerry J Vahala
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA, USA
| | - Franklyn Quinlan
- National Institute of Standards and Technology, Boulder, CO, USA
- Electrical Computer & Energy Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Scott A Diddams
- National Institute of Standards and Technology, Boulder, CO, USA.
- Department of Physics, University of Colorado Boulder, Boulder, CO, USA.
- Electrical Computer & Energy Engineering, University of Colorado Boulder, Boulder, CO, USA.
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5
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Sun S, Wang B, Liu K, Harrington MW, Tabatabaei F, Liu R, Wang J, Hanifi S, Morgan JS, Jahanbozorgi M, Yang Z, Bowers SM, Morton PA, Nelson KD, Beling A, Blumenthal DJ, Yi X. Integrated optical frequency division for microwave and mmWave generation. Nature 2024; 627:540-545. [PMID: 38448598 PMCID: PMC10954543 DOI: 10.1038/s41586-024-07057-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 01/10/2024] [Indexed: 03/08/2024]
Abstract
The generation of ultra-low-noise microwave and mmWave in miniaturized, chip-based platforms can transform communication, radar and sensing systems1-3. Optical frequency division that leverages optical references and optical frequency combs has emerged as a powerful technique to generate microwaves with superior spectral purity than any other approaches4-7. Here we demonstrate a miniaturized optical frequency division system that can potentially transfer the approach to a complementary metal-oxide-semiconductor-compatible integrated photonic platform. Phase stability is provided by a large mode volume, planar-waveguide-based optical reference coil cavity8,9 and is divided down from optical to mmWave frequency by using soliton microcombs generated in a waveguide-coupled microresonator10-12. Besides achieving record-low phase noise for integrated photonic mmWave oscillators, these devices can be heterogeneously integrated with semiconductor lasers, amplifiers and photodiodes, holding the potential of large-volume, low-cost manufacturing for fundamental and mass-market applications13.
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Affiliation(s)
- Shuman Sun
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA
| | - Beichen Wang
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA
| | - Kaikai Liu
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Mark W Harrington
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Fatemehsadat Tabatabaei
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA
| | - Ruxuan Liu
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA
| | - Jiawei Wang
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Samin Hanifi
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA
| | - Jesse S Morgan
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA
| | - Mandana Jahanbozorgi
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA
| | - Zijiao Yang
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA
- Department of Physics, University of Virginia, Charlottesville, VA, USA
| | - Steven M Bowers
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA
| | | | | | - Andreas Beling
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA
| | - Daniel J Blumenthal
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA, USA.
| | - Xu Yi
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA.
- Department of Physics, University of Virginia, Charlottesville, VA, USA.
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6
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Shekhar S, Bogaerts W, Chrostowski L, Bowers JE, Hochberg M, Soref R, Shastri BJ. Roadmapping the next generation of silicon photonics. Nat Commun 2024; 15:751. [PMID: 38272873 PMCID: PMC10811194 DOI: 10.1038/s41467-024-44750-0] [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: 05/04/2023] [Accepted: 01/03/2024] [Indexed: 01/27/2024] Open
Abstract
Silicon photonics has developed into a mainstream technology driven by advances in optical communications. The current generation has led to a proliferation of integrated photonic devices from thousands to millions-mainly in the form of communication transceivers for data centers. Products in many exciting applications, such as sensing and computing, are around the corner. What will it take to increase the proliferation of silicon photonics from millions to billions of units shipped? What will the next generation of silicon photonics look like? What are the common threads in the integration and fabrication bottlenecks that silicon photonic applications face, and which emerging technologies can solve them? This perspective article is an attempt to answer such questions. We chart the generational trends in silicon photonics technology, drawing parallels from the generational definitions of CMOS technology. We identify the crucial challenges that must be solved to make giant strides in CMOS-foundry-compatible devices, circuits, integration, and packaging. We identify challenges critical to the next generation of systems and applications-in communication, signal processing, and sensing. By identifying and summarizing such challenges and opportunities, we aim to stimulate further research on devices, circuits, and systems for the silicon photonics ecosystem.
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Affiliation(s)
- Sudip Shekhar
- Department of Electrical & Computer Engineering, University of British Columbia, 2332 Main Mall, Vancouver, V6T1Z4, BC, Canada.
| | - Wim Bogaerts
- Department of Information Technology, Ghent University - IMEC, Technologiepark-Zwijnaarde 126, Ghent, 9052, Belgium
| | - Lukas Chrostowski
- Department of Electrical & Computer Engineering, University of British Columbia, 2332 Main Mall, Vancouver, V6T1Z4, BC, Canada
| | - John E Bowers
- Department of Electrical & Computer Engineering, University of California Santa Barbara, Santa Barbara, 93106, CA, USA
| | - Michael Hochberg
- Luminous Computing, 4750 Patrick Henry Drive, Santa Clara, 95054, CA, USA
| | - Richard Soref
- College of Science and Mathematics, University of Massachusetts Boston, 100 William T. Morrissey Blvd., Boston, 02125, MA, USA
| | - Bhavin J Shastri
- Department of Physics, Engineering Physics & Astronomy, Queen's University, 64 Bader Lane, Kingston, K7L3N6, ON, Canada.
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7
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Liu K, Wang J, Chauhan N, Harrington MW, Nelson KD, Blumenthal DJ. Integrated photonic molecule Brillouin laser with a high-power sub-100-mHz fundamental linewidth. OPTICS LETTERS 2024; 49:45-48. [PMID: 38134148 DOI: 10.1364/ol.503126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 11/05/2023] [Indexed: 12/24/2023]
Abstract
Photonic integrated lasers with an ultra-low fundamental linewidth and a high output power are important for precision atomic and quantum applications, high-capacity communications, and fiber sensing, yet wafer-scale solutions have remained elusive. Here we report an integrated stimulated Brillouin laser (SBL), based on a photonic molecule coupled resonator design, that achieves a sub-100-mHz fundamental linewidth with greater than 10-mW output power in the C band, fabricated on a 200-mm silicon nitride (Si3N4) CMOS-foundry compatible wafer-scale platform. The photonic molecule design is used to suppress the second-order Stokes (S2) emission, allowing the primary lasing mode to increase with the pump power without phase noise feedback from higher Stokes orders. The nested waveguide resonators have a 184 million intrinsic and 92 million loaded Q, over an order of magnitude improvement over prior photonic molecules, enabling precision resonance splitting of 198 MHz at the S2 frequency. We demonstrate S2-suppressed single-mode SBL with a minimum fundamental linewidth of 71±18 mHz, corresponding to a 23±6-mHz2/Hz white-frequency-noise floor, over an order of magnitude lower than prior integrated SBLs, with an ∼11-mW output power and 2.3-mW threshold power. The frequency noise reaches the resonator-intrinsic thermo-refractive noise from 2-kHz to 1-MHz offset. The laser phase noise reaches -155 dBc/Hz at 10-MHz offset. The performance of this chip-scale SBL shows promise not only to improve the reliability and reduce size and cost but also to enable new precision experiments that require the high-speed manipulation, control, and interrogation of atoms and qubits. Realization in the silicon nitride ultra-low loss platform is adaptable to a wide range of wavelengths from the visible to infrared and enables integration with other components for systems-on-chip solutions for a wide range of precision scientific and engineering applications including quantum sensing, gravitometers, atom interferometers, precision metrology, optical atomic clocks, and ultra-low noise microwave generation.
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8
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Xu Y, Wang H, Guo J, Zhang J, Zhou W, Shen D. Laser frequency stabilization based on Fano resonance in a microcylinder cavity. OPTICS LETTERS 2023; 48:4288-4291. [PMID: 37582014 DOI: 10.1364/ol.497792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 07/24/2023] [Indexed: 08/17/2023]
Abstract
We investigate the application of Fano resonance in microcylinder cavities for laser frequency stabilization. By combining Fano resonance and the differential subtraction method, we successfully reproduce the error signal of the traditional Pound-Drever-Hall (PDH) technique. The frequency noise of the laser, when locked to both microsphere and microcylinder cavities, approaches the thermal noise limit. The microcylinder cavity, with a high Q factor of ∼108, benefiting from its large mode volume, exhibits a significant reduction in frequency noise by one order of magnitude compared with a microsphere in the frequency range of 0.1 to 10 kHz, achieving a minimum noise of ∼2.25 Hz2/Hz at 10 kHz. As this approach eliminates the need for additional electronic circuits typically used in the PDH technique, it holds promise as a cost-effective and reliable solution for laser frequency stabilization.
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9
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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.
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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.
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10
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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.
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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.
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11
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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.
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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
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12
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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.
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13
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Snigirev V, Riedhauser A, Lihachev G, Churaev M, Riemensberger J, Wang RN, Siddharth A, Huang G, Möhl C, Popoff Y, Drechsler U, Caimi D, Hönl S, Liu J, Seidler P, Kippenberg TJ. Ultrafast tunable lasers using lithium niobate integrated photonics. Nature 2023; 615:411-417. [PMID: 36922611 PMCID: PMC10017507 DOI: 10.1038/s41586-023-05724-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 01/11/2023] [Indexed: 03/17/2023]
Abstract
Early works1 and recent advances in thin-film lithium niobate (LiNbO3) on insulator have enabled low-loss photonic integrated circuits2,3, modulators with improved half-wave voltage4,5, electro-optic frequency combs6 and on-chip electro-optic devices, with applications ranging from microwave photonics to microwave-to-optical quantum interfaces7. Although recent advances have demonstrated tunable integrated lasers based on LiNbO3 (refs. 8,9), the full potential of this platform to demonstrate frequency-agile, narrow-linewidth integrated lasers has not been achieved. Here we report such a laser with a fast tuning rate based on a hybrid silicon nitride (Si3N4)-LiNbO3 photonic platform and demonstrate its use for coherent laser ranging. Our platform is based on heterogeneous integration of ultralow-loss Si3N4 photonic integrated circuits with thin-film LiNbO3 through direct bonding at the wafer level, in contrast to previously demonstrated chiplet-level integration10, featuring low propagation loss of 8.5 decibels per metre, enabling narrow-linewidth lasing (intrinsic linewidth of 3 kilohertz) by self-injection locking to a laser diode. The hybrid mode of the resonator allows electro-optic laser frequency tuning at a speed of 12 × 1015 hertz per second with high linearity and low hysteresis while retaining the narrow linewidth. Using a hybrid integrated laser, we perform a proof-of-concept coherent optical ranging (FMCW LiDAR) experiment. Endowing Si3N4 photonic integrated circuits with LiNbO3 creates a platform that combines the individual advantages of thin-film LiNbO3 with those of Si3N4, which show precise lithographic control, mature manufacturing and ultralow loss11,12.
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Affiliation(s)
- Viacheslav Snigirev
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
- Center for Quantum Science and Engineering, EPFL, Lausanne, Switzerland
| | | | - Grigory Lihachev
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
- Center for Quantum Science and Engineering, EPFL, Lausanne, Switzerland
| | - Mikhail Churaev
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
- Center for Quantum Science and Engineering, EPFL, Lausanne, Switzerland
| | - Johann Riemensberger
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
- Center for Quantum Science and Engineering, EPFL, Lausanne, Switzerland
- Deep Light SA
| | - Rui Ning Wang
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
- Center for Quantum Science and Engineering, EPFL, Lausanne, Switzerland
| | - Anat Siddharth
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
- Center for Quantum Science and Engineering, EPFL, Lausanne, Switzerland
| | - Guanhao Huang
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
- Center for Quantum Science and Engineering, EPFL, Lausanne, Switzerland
| | - Charles Möhl
- IBM Research - Europe, Zurich, Ruschlikon, Switzerland
| | - Youri Popoff
- IBM Research - Europe, Zurich, Ruschlikon, Switzerland
- Integrated Systems Laboratory, Swiss Federal Institute of Technology Zurich (ETH Zürich), Zurich, Switzerland
| | - Ute Drechsler
- IBM Research - Europe, Zurich, Ruschlikon, Switzerland
| | - Daniele Caimi
- IBM Research - Europe, Zurich, Ruschlikon, Switzerland
| | - Simon Hönl
- IBM Research - Europe, Zurich, Ruschlikon, Switzerland
| | - Junqiu Liu
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
- Center for Quantum Science and Engineering, EPFL, Lausanne, Switzerland
| | - Paul Seidler
- IBM Research - Europe, Zurich, Ruschlikon, Switzerland.
| | - Tobias J Kippenberg
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland.
- Center for Quantum Science and Engineering, EPFL, Lausanne, Switzerland.
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14
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Zhou Z, Ou X, Fang Y, Alkhazraji E, Xu R, Wan Y, Bowers JE. Prospects and applications of on-chip lasers. ELIGHT 2023; 3:1. [PMID: 36618904 PMCID: PMC9810524 DOI: 10.1186/s43593-022-00027-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 09/03/2022] [Accepted: 09/05/2022] [Indexed: 01/05/2023]
Abstract
Integrated silicon photonics has sparked a significant ramp-up of investment in both academia and industry as a scalable, power-efficient, and eco-friendly solution. At the heart of this platform is the light source, which in itself, has been the focus of research and development extensively. This paper sheds light and conveys our perspective on the current state-of-the-art in different aspects of application-driven on-chip silicon lasers. We tackle this from two perspectives: device-level and system-wide points of view. In the former, the different routes taken in integrating on-chip lasers are explored from different material systems to the chosen integration methodologies. Then, the discussion focus is shifted towards system-wide applications that show great prospects in incorporating photonic integrated circuits (PIC) with on-chip lasers and active devices, namely, optical communications and interconnects, optical phased array-based LiDAR, sensors for chemical and biological analysis, integrated quantum technologies, and finally, optical computing. By leveraging the myriad inherent attractive features of integrated silicon photonics, this paper aims to inspire further development in incorporating PICs with on-chip lasers in, but not limited to, these applications for substantial performance gains, green solutions, and mass production.
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Affiliation(s)
- Zhican Zhou
- Integrated Photonics Lab, King Abdullah University of Science and Technology, Thuwal, Makkah Province Saudi Arabia
| | - Xiangpeng Ou
- Integrated Photonics Lab, King Abdullah University of Science and Technology, Thuwal, Makkah Province Saudi Arabia
| | - Yuetong Fang
- Function Hub, The Hong Kong University of Science and Technology (Guangzhou), Guangdong, China
| | - Emad Alkhazraji
- Integrated Photonics Lab, King Abdullah University of Science and Technology, Thuwal, Makkah Province Saudi Arabia
| | - Renjing Xu
- Function Hub, The Hong Kong University of Science and Technology (Guangzhou), Guangdong, China
| | - Yating Wan
- Integrated Photonics Lab, King Abdullah University of Science and Technology, Thuwal, Makkah Province Saudi Arabia
- Institute for Energy Efficiency, University of California, Santa Barbara, Santa Barbara, CA 93106 USA
| | - John E. Bowers
- Institute for Energy Efficiency, University of California, Santa Barbara, Santa Barbara, CA 93106 USA
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15
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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.
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16
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Geng Y, Xiao Y, Bai Q, Han X, Dong W, Wang W, Xue J, Yao B, Deng G, Zhou Q, Qiu K, Xu J, Zhou H. Wavelength-division multiplexing communications using integrated soliton microcomb laser source. OPTICS LETTERS 2022; 47:6129-6132. [PMID: 37219189 DOI: 10.1364/ol.475075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 10/31/2022] [Indexed: 05/24/2023]
Abstract
In this Letter, we report an investigation of the feasibility and performance of wavelength-division multiplexed (WDM) optical communications using an integrated perfect soliton crystal as the multi-channel laser source. First, we confirm that perfect soliton crystals pumped directly by a distributed-feedback (DFB) laser self-injection locked to the host microcavity has sufficiently low frequency and amplitude noise to encode advanced data formats. Second, perfect soliton crystals are exploited to boost the power level of each microcomb line, so that it can be directly used for data modulation, excluding preamplification. Third, in a proof-of-concept experiment, we demonstrate seven-channel 16-quadrature amplitude modulation (16-QAM) and 4-level pulse amplitude modulation (PAM4) data transmissions using an integrated perfect soliton crystal as the laser carrier; excellent data receiving performance is obtained for various fiber link distances and amplifier configurations. Our study reveals that fully integrated Kerr soliton microcombs are viable and advantageous for optical data communications.
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17
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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.
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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
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18
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Extending the spectrum of fully integrated photonics to submicrometre wavelengths. Nature 2022; 610:54-60. [PMID: 36171286 PMCID: PMC9534754 DOI: 10.1038/s41586-022-05119-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 07/18/2022] [Indexed: 11/24/2022]
Abstract
Integrated photonics has profoundly affected a wide range of technologies underpinning modern society1–4. The ability to fabricate a complete optical system on a chip offers unrivalled scalability, weight, cost and power efficiency5,6. Over the last decade, the progression from pure III–V materials platforms to silicon photonics has significantly broadened the scope of integrated photonics, by combining integrated lasers with the high-volume, advanced fabrication capabilities of the commercial electronics industry7,8. Yet, despite remarkable manufacturing advantages, reliance on silicon-based waveguides currently limits the spectral window available to photonic integrated circuits (PICs). Here, we present a new generation of integrated photonics by directly uniting III–V materials with silicon nitride waveguides on Si wafers. Using this technology, we present a fully integrated PIC at photon energies greater than the bandgap of silicon, demonstrating essential photonic building blocks, including lasers, amplifiers, photodetectors, modulators and passives, all operating at submicrometre wavelengths. Using this platform, we achieve unprecedented coherence and tunability in an integrated laser at short wavelength. Furthermore, by making use of this higher photon energy, we demonstrate superb high-temperature performance and kHz-level fundamental linewidths at elevated temperatures. Given the many potential applications at short wavelengths, the success of this integration strategy unlocks a broad range of new integrated photonics applications. Fully integrated photonics at submicrometre wavelengths is realized by a heterogeneous integration technology.
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19
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Yuan Z, Wang H, Liu P, Li B, Shen B, Gao M, Chang L, Jin W, Feshali A, Paniccia M, Bowers J, Vahala K. Correlated self-heterodyne method for ultra-low-noise laser linewidth measurements. OPTICS EXPRESS 2022; 30:25147-25161. [PMID: 36237052 DOI: 10.1364/oe.458109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 06/14/2022] [Indexed: 06/16/2023]
Abstract
Narrow-linewidth lasers are important to many applications spanning precision metrology to sensing systems. Characterization of these lasers requires precise measurements of their frequency noise spectra. Here we demonstrate a correlated self-heterodyne (COSH) method capable of measuring frequency noise as low as 0.01 Hz2/Hz at 1 MHz offset frequency. The measurement setup is characterized by both commercial and lab-built lasers, and features low optical power requirements, fast acquisition time and high intensity noise rejection.
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20
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Loh W, Kharas D, Maxson R, West GN, Medeiros A, Braje D, Juodawlkis PW, McConnell R. Cooling of an integrated Brillouin laser below the thermal limit. OPTICS EXPRESS 2022; 30:22562-22571. [PMID: 36224951 DOI: 10.1364/oe.451622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 05/17/2022] [Indexed: 06/16/2023]
Abstract
Photonically integrated resonators are promising as a platform for enabling ultranarrow linewidth lasers in a compact form factor. Owing to their small size, these integrated resonators suffer from thermal noise that limits the frequency stability of the optical mode to ∼100 kHz. Here, we demonstrate an integrated stimulated Brillouin scattering (SBS) laser based on a large mode-volume annulus resonator that realizes an ultranarrow thermal-noise-limited linewidth of 270 Hz. In practice, yet narrower linewidths are required before integrated lasers can be truly useful for applications such as optical atomic clocks, quantum computing, gravitational wave detection, and precision spectroscopy. To this end, we employ a thermorefractive noise suppression technique utilizing an auxiliary laser to reduce our SBS laser linewidth to 70 Hz. This demonstration showcases the possibility of stabilizing the thermal motion of even the narrowest linewidth chip lasers to below 100 Hz, thereby opening the door to making integrated microresonators practical for the most demanding future scientific endeavors.
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21
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Lihachev G, Riemensberger J, Weng W, Liu J, Tian H, Siddharth A, Snigirev V, Shadymov V, Voloshin A, Wang RN, He J, Bhave SA, Kippenberg TJ. Low-noise frequency-agile photonic integrated lasers for coherent ranging. Nat Commun 2022; 13:3522. [PMID: 35725718 PMCID: PMC9209488 DOI: 10.1038/s41467-022-30911-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 05/24/2022] [Indexed: 11/27/2022] Open
Abstract
Frequency modulated continuous wave laser ranging (FMCW LiDAR) enables distance mapping with simultaneous position and velocity information, is immune to stray light, can achieve long range, operate in the eye-safe region of 1550 nm and achieve high sensitivity. Despite its advantages, it is compounded by the simultaneous requirement of both narrow linewidth low noise lasers that can be precisely chirped. While integrated silicon-based lasers, compatible with wafer scale manufacturing in large volumes at low cost, have experienced major advances and are now employed on a commercial scale in data centers, and impressive progress has led to integrated lasers with (ultra) narrow sub-100 Hz-level intrinsic linewidth based on optical feedback from photonic circuits, these lasers presently lack fast nonthermal tuning, i.e. frequency agility as required for coherent ranging. Here, we demonstrate a hybrid photonic integrated laser that exhibits very narrow intrinsic linewidth of 25 Hz while offering linear, hysteresis-free, and mode-hop-free-tuning beyond 1 GHz with up to megahertz actuation bandwidth constituting 1.6 × 1015 Hz/s tuning speed. Our approach uses foundry-based technologies - ultralow-loss (1 dB/m) Si3N4 photonic microresonators, combined with aluminium nitride (AlN) or lead zirconium titanate (PZT) microelectromechanical systems (MEMS) based stress-optic actuation. Electrically driven low-phase-noise lasing is attained by self-injection locking of an Indium Phosphide (InP) laser chip and only limited by fundamental thermo-refractive noise at mid-range offsets. By utilizing difference-drive and apodization of the photonic chip to suppress mechanical vibrations of the chip, a flat actuation response up to 10 MHz is achieved. We leverage this capability to demonstrate a compact coherent LiDAR engine that can generate up to 800 kHz FMCW triangular optical chirp signals, requiring neither any active linearization nor predistortion compensation, and perform a 10 m optical ranging experiment, with a resolution of 12.5 cm. Our results constitute a photonic integrated laser system for scenarios where high compactness, fast frequency actuation, and high spectral purity are required. Stable and tunable integrated lasers are fundamental building blocks for applications from spectroscopy to imaging and communication. Here the authors present a narrow linewidth hybrid photonic integrated laser with low frequency noise and fast linear wavelength tuning. They then provide an efficient FMCW LIDAR demonstration.
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Affiliation(s)
- Grigory Lihachev
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Johann Riemensberger
- 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.,Institute for Photonics and Advanced Sensing (IPAS), and School of Physical Sciences, The University of Adelaide, Adelaide, South Australia, 5005, Australia
| | - Junqiu Liu
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Hao Tian
- OxideMEMS Lab, Purdue University, West Lafayette, IN, 47907, USA
| | - Anat Siddharth
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Viacheslav Snigirev
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Vladimir Shadymov
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Andrey Voloshin
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Rui Ning Wang
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Jijun He
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Sunil A Bhave
- OxideMEMS Lab, Purdue University, West Lafayette, IN, 47907, USA
| | - Tobias J Kippenberg
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015, Lausanne, Switzerland.
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22
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Far Brusatori M, Duplat DN, Degli-Eredi I, Nielsen L, Tønning PL, Castera P, Volet N, Heck MJR. Ultralow-linewidth ring laser using hybrid integration and generic foundry platforms. OPTICS LETTERS 2022; 47:2686-2689. [PMID: 35648905 DOI: 10.1364/ol.457367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/01/2022] [Indexed: 06/15/2023]
Abstract
Two photonic integrated circuits (PICs) are coupled to form a hybridly integrated semiconductor ring laser in the telecom C band with an intrinsic linewidth of (158±21) Hz. This is, to the best of our knowledge, the first time an InP active-passive platform is used in conjunction with an integrated low-loss resonator to obtain a narrow-linewidth laser implemented using generic foundry platforms. The presented results pave the way for a hybrid integrated platform for microwave photonics (MWP), as the demonstrated device includes multiple active-passive components, and its narrow optical linewidth can potentially be translated to a narrow-linewidth microwave signal. Furthermore, as the laser is based on hybrid integration of two PICs from generic foundry platforms, there is a path to reproducible and low-cost devices.
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23
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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.
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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
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Dynamics of Semiconductor Lasers under External Optical Feedback from Both Sides of the Laser Cavity. PHOTONICS 2022. [DOI: 10.3390/photonics9010043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
To increase the spectral efficiency of coherent communication systems, lasers with ever-narrower linewidths are required as they enable higher-order modulation formats with lower bit-error rates. In particular, semiconductor lasers are a key component due to their compactness, low power consumption, and potential for mass production. In field-testing scenarios their output is coupled to a fiber, making them susceptible to external optical feedback (EOF). This has a detrimental effect on its stability, thus it is traditionally countered by employing, for example, optical isolators and angled output waveguides. In this work, EOF is explored in a novel way with the aim to reduce and stabilize the laser linewidth. EOF has been traditionally studied in the case where it is applied to only one side of the laser cavity. In contrast, this work gives a generalization to the case of feedback on both sides. It is implemented using photonic components available via generic foundry platforms, thus creating a path towards devices with high technology-readiness level. Numerical results shows an improvement in performance of the double-feedback case with respect to the single-feedback case. In particularly, by appropriately selecting the phase of the feedback from both sides, a broad stability regime is discovered. This work paves the way towards low-cost, integrated and stable narrow-linewidth integrated lasers.
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