1
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Yang J, Van Gasse K, Lukin DM, Guidry MA, Ahn GH, White AD, Vučković J. Titanium:sapphire-on-insulator integrated lasers and amplifiers. Nature 2024; 630:853-859. [PMID: 38926612 DOI: 10.1038/s41586-024-07457-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 04/23/2024] [Indexed: 06/28/2024]
Abstract
Titanium:sapphire (Ti:sapphire) lasers have been essential for advancing fundamental research and technological applications, including the development of the optical frequency comb1, two-photon microscopy2 and experimental quantum optics3,4. Ti:sapphire lasers are unmatched in bandwidth and tuning range, yet their use is restricted because of their large size, cost and need for high optical pump powers5. Here we demonstrate a monocrystalline titanium:sapphire-on-insulator (Ti:SaOI) photonics platform that enables dramatic miniaturization, cost reduction and scalability of Ti:sapphire technology. First, through the fabrication of low-loss whispering-gallery-mode resonators, we realize a Ti:sapphire laser operating with an ultralow, sub-milliwatt lasing threshold. Then, through orders-of-magnitude improvement in mode confinement in Ti:SaOI waveguides, we realize an integrated solid-state (that is, non-semiconductor) optical amplifier operating below 1 μm. We demonstrate unprecedented distortion-free amplification of picosecond pulses to peak powers reaching 1.0 kW. Finally, we demonstrate a tunable integrated Ti:sapphire laser, which can be pumped with low-cost, miniature, off-the-shelf green laser diodes. This opens the doors to new modalities of Ti:sapphire lasers, such as massively scalable Ti:sapphire laser-array systems for several applications. As a proof-of-concept demonstration, we use a Ti:SaOI laser array as the sole optical control for a cavity quantum electrodynamics experiment with artificial atoms in silicon carbide6. This work is a key step towards the democratization of Ti:sapphire technology through a three-orders-of-magnitude reduction in cost and footprint and introduces solid-state broadband amplification of sub-micron wavelength light.
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Affiliation(s)
- Joshua Yang
- E. L. Ginzton Laboratory, Stanford University, Stanford, CA, USA
| | - Kasper Van Gasse
- E. L. Ginzton Laboratory, Stanford University, Stanford, CA, USA
- Photonics Research Group, Ghent University-imec, Ghent, Belgium
| | - Daniil M Lukin
- E. L. Ginzton Laboratory, Stanford University, Stanford, CA, USA
| | - Melissa A Guidry
- E. L. Ginzton Laboratory, Stanford University, Stanford, CA, USA
| | - Geun Ho Ahn
- E. L. Ginzton Laboratory, Stanford University, Stanford, CA, USA
| | | | - Jelena Vučković
- E. L. Ginzton Laboratory, Stanford University, Stanford, CA, USA.
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2
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Gao M, Lüpken NM, Fallnich C. Highly efficient and widely tunable Si 3N 4 waveguide-based optical parametric oscillator. OPTICS EXPRESS 2024; 32:10899-10909. [PMID: 38570952 DOI: 10.1364/oe.515511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 02/05/2024] [Indexed: 04/05/2024]
Abstract
We demonstrate an efficient and widely tunable synchronously pumped optical parametric oscillator (OPO) exploiting four-wave mixing (FWM) in a silicon nitride (Si3N4) waveguide with inverted tapers. At a pump pulse duration of 2 ps, the waveguide-based OPO (WOPO) exhibited a high external pump-to-idler conversion efficiency of up to -7.64 dB at 74% pump depletion and a generation of up to 387 pJ output idler pulse energy around 1.13 μm wavelength. Additionally, the parametric oscillation resulted in a 64 dB amplification of idler power spectral density in comparison to spontaneous FWM, allowing for a wide idler wavelength tunability of 191 nm around 1.15 μm. Our WOPO represents a significant improvement of conversion efficiency as well as output energy among χ3 WOPOs, rendering an important step towards a highly efficient and widely tunable chip-based light source for, e.g., coherent anti-Stokes Raman scattering.
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3
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Ren K, Guo Y, Zhai Y, Zhang L. On-chip octave-spanning flat supercontinuum in all-normal-dispersion silicon nitride waveguides. OPTICS EXPRESS 2024; 32:8527-8536. [PMID: 38571110 DOI: 10.1364/oe.509430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 01/23/2024] [Indexed: 04/05/2024]
Abstract
On-chip supercontinuum generators have emerged as an attractive optical source with small size, broad spectrum and high power efficiency. Nevertheless, there has long been a trade-off between spectral uniformity and bandwidth. We propose a novel silicon nitride waveguide with flat saddle-shaped all-normal dispersion, particularly for enhancing the nonlinear interactions over a wide band. By launching a 250-fs 30-kW input pulse, an ultra-flat (-6 dB) octave-spanning supercontinuum extending from 638 nm to 1477 nm can be generated. We analyze the performance of the supercontinuum generator in terms of spectral flatness and bandwidth under different input pulse conditions. Thanks to mature dispersion engineering, the pump wavelength can be flexibly selected within the flat dispersion region. The generated supercontinuum, therefore, can be applied to different spectral regions by shifting the center wavelength.
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4
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Ayan A, Liu J, Kippenberg TJ, Brès CS. Towards efficient broadband parametric conversion in ultra-long Si 3N 4 waveguides. OPTICS EXPRESS 2023; 31:40916-40927. [PMID: 38041380 DOI: 10.1364/oe.502648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 10/05/2023] [Indexed: 12/03/2023]
Abstract
Broadband continuous-wave parametric gain and efficient wavelength conversion is an important functionality to bring on-chip. Recently, meter-long silicon nitride waveguides have been utilized to obtain continuous-traveling-wave parametric gain, establishing the great potential of photonic-integrated-circuit-based parametric amplifiers. However, the effect of spiral structure on the performance and achievable bandwidth of such devices have not yet been studied. In this work, we investigate the efficiency-bandwidth performance in up to 2 meter-long waveguides engineered for broadband operation. Moreover, we analyze the conversion efficiency fluctuations that have been observed in meter-long Si3N4 waveguides and study the use of temperature control to limit the fluctuations.
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5
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Brès CS, Della Torre A, Grassani D, Brasch V, Grillet C, Monat C. Supercontinuum in integrated photonics: generation, applications, challenges, and perspectives. NANOPHOTONICS 2023; 12:1199-1244. [PMID: 36969949 PMCID: PMC10031268 DOI: 10.1515/nanoph-2022-0749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/20/2023] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
Frequency conversion in nonlinear materials is an extremely useful solution to the generation of new optical frequencies. Often, it is the only viable solution to realize light sources highly relevant for applications in science and industry. In particular, supercontinuum generation in waveguides, defined as the extreme spectral broadening of an input pulsed laser light, is a powerful technique to bridge distant spectral regions based on single-pass geometry, without requiring additional seed lasers or temporal synchronization. Owing to the influence of dispersion on the nonlinear broadening physics, supercontinuum generation had its breakthrough with the advent of photonic crystal fibers, which permitted an advanced control of light confinement, thereby greatly improving our understanding of the underlying phenomena responsible for supercontinuum generation. More recently, maturing in fabrication of photonic integrated waveguides has resulted in access to supercontinuum generation platforms benefiting from precise lithographic control of dispersion, high yield, compact footprint, and improved power consumption. This Review aims to present a comprehensive overview of supercontinuum generation in chip-based platforms, from underlying physics mechanisms up to the most recent and significant demonstrations. The diversity of integrated material platforms, as well as specific features of waveguides, is opening new opportunities, as will be discussed here.
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Affiliation(s)
- Camille-Sophie Brès
- Photonic Systems Laboratory (PHOSL), Ecole Polytechnique Fédérale de Lausanne, 1015Lausanne, Switzerland
| | - Alberto Della Torre
- Université de Lyon, Institut des Nanotechnologies de Lyon (INL) UMR CNRS 5270, Ecole Centrale de Lyon, 69131Ecully, France
| | - Davide Grassani
- Centre Suisse d’Electronique et de Microtechnique (CSEM), 2000Neuchâtel, Switzerland
| | | | - Christian Grillet
- Université de Lyon, Institut des Nanotechnologies de Lyon (INL) UMR CNRS 5270, Ecole Centrale de Lyon, 69131Ecully, France
| | - Christelle Monat
- Université de Lyon, Institut des Nanotechnologies de Lyon (INL) UMR CNRS 5270, Ecole Centrale de Lyon, 69131Ecully, France
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6
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Chen Z, Fainman Y. Compensation of Kerr-induced impairments in silicon nitride third-harmonic generators. OPTICS EXPRESS 2023; 31:5229-5241. [PMID: 36823809 DOI: 10.1364/oe.479059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 01/12/2023] [Indexed: 06/18/2023]
Abstract
Integrated third-harmonic generators enable on-chip wavelength conversion translating telecom signals to the visible spectrum. Despite the desirable functionality, the device performance is susceptible to phase distortions. Here, we present a design method of compensating the Kerr-induced distortions in third-harmonic generation. The design method yields a chirped Bragg grating theoretically improving the conversion efficiency by ∼30 dB. We envision the design method will pave the way for demonstrating efficient infrared-to-visible upconversion in silicon nitride chips.
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7
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Martins IS, Silva HF, Lazareva EN, Chernomyrdin NV, Zaytsev KI, Oliveira LM, Tuchin VV. Measurement of tissue optical properties in a wide spectral range: a review [Invited]. BIOMEDICAL OPTICS EXPRESS 2023; 14:249-298. [PMID: 36698664 PMCID: PMC9841994 DOI: 10.1364/boe.479320] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 11/29/2022] [Accepted: 11/29/2022] [Indexed: 06/17/2023]
Abstract
A distinctive feature of this review is a critical analysis of methods and results of measurements of the optical properties of tissues in a wide spectral range from deep UV to terahertz waves. Much attention is paid to measurements of the refractive index of biological tissues and liquids, the knowledge of which is necessary for the effective application of many methods of optical imaging and diagnostics. The optical parameters of healthy and pathological tissues are presented, and the reasons for their differences are discussed, which is important for the discrimination of pathologies and the demarcation of their boundaries. When considering the interaction of terahertz radiation with tissues, the concept of an effective medium is discussed, and relaxation models of the effective optical properties of tissues are presented. Attention is drawn to the manifestation of the scattering properties of tissues in the THz range and the problems of measuring the optical properties of tissues in this range are discussed. In conclusion, a method for the dynamic analysis of the optical properties of tissues under optical clearing using an application of immersion agents is presented. The main mechanisms and technologies of optical clearing, as well as examples of the successful application for differentiation of healthy and pathological tissues, are analyzed.
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Affiliation(s)
- Inês S. Martins
- Center for Innovation in Engineering and Industrial Technology, ISEP, Porto, Portugal
| | - Hugo F. Silva
- Porto University, School of Engineering, Porto, Portugal
| | - Ekaterina N. Lazareva
- Science Medical Center, Saratov State University, Saratov, Russia
- Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, Tomsk, Russia
| | | | - Kirill I. Zaytsev
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russia
| | - Luís M. Oliveira
- Physics Department, Polytechnic of Porto – School of Engineering (ISEP), Porto, Portugal
- Institute for Systems and Computer Engineering, Technology and Science (INESC TEC), Porto, Portugal
| | - Valery V. Tuchin
- Science Medical Center, Saratov State University, Saratov, Russia
- Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, Tomsk, Russia
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8
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Ostapenko H, Mitchell T, Castro-Marin P, Reid DT. Three-element, self-starting Kerr-lens-modelocked 1-GHz Ti:sapphire oscillator pumped by a single laser diode. OPTICS EXPRESS 2022; 30:39624-39630. [PMID: 36298909 DOI: 10.1364/oe.472533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
We present a Kerr-lens-modelocked, three-element, diode-pumped Ti:sapphire laser producing 111-fs pulses at a repetition frequency of 1.02 GHz. Self-starting soliton-modelocked operation with an output power of 106 mW was obtained when the laser was pumped at 1.0 W with a single 527-nm laser diode. The output exhibits a relative intensity noise of 0.06% (1 Hz - 1 MHz) and locking of the repetition rate to an external reference is demonstrated with a phase error of 1.7 mrad (1 Hz-1 MHz). The simplicity of the laser makes it an attractive candidate as a module for integration into larger systems.
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9
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Li M, Hong L, Li ZY. Intense Two-Octave Ultraviolet-Visible-Infrared Supercontinuum Laser via High-Efficiency One-Octave Second-Harmonic Generation. Research (Wash D C) 2022; 2022:9871729. [PMID: 35935139 PMCID: PMC9275071 DOI: 10.34133/2022/9871729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 05/19/2022] [Indexed: 11/24/2022] Open
Abstract
Intense ultrabroadband laser source of high pulse energy has attracted more and more attention in physics, chemistry, biology, material science, and other disciplines. We report design and realization of a chirped periodically poled lithium niobate nonlinear crystal that supports ultrabroadband second-harmonic generation covering 350-850 nm by implementing simultaneously up to 12 orders of quasiphase matching against ultrabroadband pump laser covering 700-1700 nm with an average high conversion efficiency of about 25.8%. We obtain a flat supercontinuum spectrum with a 10 dB bandwidth covering more than one octave (about 375-1200 nm) and 20 dB bandwidth covering more than two octaves (about 350-1500 nm) in the ultraviolet-visible-infrared regime and having intense energy as 0.17 mJ per pulse through synergic action of second-order and third-order nonlinearity under pump of 0.48 mJ per pulse Ti:sapphire femtosecond laser. This scheme would provide a promising method for the construction of supercontinuum laser source with extremely broad bandwidth, large pulse energy, and high peak power for a variety of basic science and high technology applications.
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Affiliation(s)
- Mingzhou Li
- School of Physics and Optoelectronics, South China University of Technology, Guangzhou 510641, China
| | - Lihong Hong
- School of Physics and Optoelectronics, South China University of Technology, Guangzhou 510641, China
| | - Zhi-Yuan Li
- School of Physics and Optoelectronics, South China University of Technology, Guangzhou 510641, China
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10
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Cao Y, Sohn BU, Gao H, Xing P, Chen GFR, Ng DKT, Tan DTH. Supercontinuum generation in a nonlinear ultra-silicon-rich nitride waveguide. Sci Rep 2022; 12:9487. [PMID: 35676414 PMCID: PMC9177728 DOI: 10.1038/s41598-022-13734-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 05/09/2022] [Indexed: 12/05/2022] Open
Abstract
Supercontinuum generation is demonstrated in a 3-mm-long ultra-silicon-rich nitride (USRN) waveguide by launching 500 fs pulses centered at 1555 nm with a pulse energy of 17 pJ. The generated supercontinuum is experimentally characterized to possess a high spectral coherence, with an average |g12| exceeding 0.90 across the wavelength range of the coherence measurement (1260 nm to 1700 nm). Numerical simulations further indicate a high coherence over the full spectrum. The experimentally measured supercontinuum agrees well with the theoretical simulations based on the generalized nonlinear Schrödinger equation. The generated broadband spectra using 500 fs pulses possessing high spectral coherence provide a promising route for CMOS-compatible light sources for self-referencing applications, metrology, and imaging.
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Affiliation(s)
- Yanmei Cao
- Photonics Devices and Systems Group, Singapore University of Technology and Design, 8 Somapah Road, Singapore, 487372, Singapore
| | - Byoung-Uk Sohn
- Photonics Devices and Systems Group, Singapore University of Technology and Design, 8 Somapah Road, Singapore, 487372, Singapore
| | - Hongwei Gao
- Photonics Devices and Systems Group, Singapore University of Technology and Design, 8 Somapah Road, Singapore, 487372, Singapore
| | - Peng Xing
- Photonics Devices and Systems Group, Singapore University of Technology and Design, 8 Somapah Road, Singapore, 487372, Singapore
| | - George F R Chen
- Photonics Devices and Systems Group, Singapore University of Technology and Design, 8 Somapah Road, Singapore, 487372, Singapore
| | - Doris K T Ng
- Institute of Microelectronics, A*STAR, 2 Fusionopolis Way, #08-02, Innovis Tower,, Singapore, 138634, Singapore
| | - Dawn T H Tan
- Photonics Devices and Systems Group, Singapore University of Technology and Design, 8 Somapah Road, Singapore, 487372, Singapore.
- Institute of Microelectronics, A*STAR, 2 Fusionopolis Way, #08-02, Innovis Tower,, Singapore, 138634, Singapore.
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11
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Rebolledo-Salgado I, Ye Z, Christensen S, Lei F, Twayana K, Schröder J, Zelan M, Torres-Company V. Coherent supercontinuum generation in all-normal dispersion Si 3N 4 waveguides. OPTICS EXPRESS 2022; 30:8641-8651. [PMID: 35299311 DOI: 10.1364/oe.450987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 02/19/2022] [Indexed: 06/14/2023]
Abstract
Spectral broadening of optical frequency combs with high repetition rate is of significant interest in optical communications, radio-frequency photonics and spectroscopy. Silicon nitride waveguides (Si3N4) in the anomalous dispersion region have shown efficient supercontinuum generation spanning an octave-bandwidth. However, the broadening mechanism in this regime is usually attained with femtosecond pulses in order to maintain the coherence. Supercontinuum generation in the normal dispersion regime is more prone to longer (ps) pulses, but the implementation in normal dispersion silicon nitride waveguides is challenging as it possesses strong requirements in propagation length and losses. Here, we experimentally demonstrate the use of a Si3N4 waveguide to perform coherent spectral broadening using pulses in the picosecond regime with high repetition rate. Moreover, our work explores the formation of optical wave breaking using a higher energy pulse which enables the generation of a coherent octave spanning spectrum. These results offer a new prospect for coherent broadening using long duration pulses and replacing bulky optical components.
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12
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El Shamy RS, Swillam MA, Li X. Optimization of Silicon Nitride Waveguide Platform for On-Chip Virus Detection. SENSORS (BASEL, SWITZERLAND) 2022; 22:1152. [PMID: 35161897 PMCID: PMC8840533 DOI: 10.3390/s22031152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/26/2022] [Accepted: 01/27/2022] [Indexed: 01/27/2023]
Abstract
This work presents a rigorous and generic sensitivity analysis of silicon nitride on silicon dioxide strip waveguide for virus detection. In general, by functionalizing the waveguide surface with a specific antibodies layer, we make the optical sensor sensitive only to a particular virus. Unlike conventional virus detection methods such as polymerase chain reaction (PCR), integrated refractive index (RI) optical sensors offer cheap and mass-scale fabrication of compact devices for fast and straightforward detection with high sensitivity and selectivity. Our numerical analysis includes a wide range of wavelengths from visible to mid-infrared. We determined the strip waveguide's single-mode dimensions and the optimum dimensions that maximize the sensitivity to the virus layer attached to its surface at each wavelength using finite difference eigenmode (FDE) solver. We also compared the strip waveguide with the widely used slot waveguide. Our theoretical study shows that silicon nitride strip waveguide working at lower wavelengths is the optimum choice for virus detection as it maximizes both the waveguide sensitivity (Swg) and the figure of merit (FOM) of the sensor. The optimized waveguides are well suited for a range of viruses with different sizes and refractive indices. Balanced Mach-Zehnder interferometer (MZI) sensors were designed using FDE solver and photonic circuit simulator at different wavelengths. The designed sensors show high FOM at λ = 450 nm ranging from 500 RIU-1 up to 1231 RIU-1 with LMZI = 500 µm. Different MZI configurations were also studied and compared. Finally, edge coupling from the fiber to the sensor was designed, showing insertion loss (IL) at λ = 450 nm of 4.1 dB for the design with FOM = 500 RIU-1. The obtained coupling efficiencies are higher than recently proposed fiber couplers.
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Affiliation(s)
- Raghi S. El Shamy
- Department of Electrical and Computer Engineering, Faculty of Engineering, McMaster University, Hamilton, ON L8S 4L8, Canada;
| | - Mohamed A. Swillam
- Department of Physics, School of Science and Engineering, The American University in Cairo, New Cairo 11835, Egypt;
| | - Xun Li
- Department of Electrical and Computer Engineering, Faculty of Engineering, McMaster University, Hamilton, ON L8S 4L8, Canada;
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13
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Sun C, Yang L, Li B, Shi W, Wang H, Chen Z, Nie X, Deng S, Ding N, Zhang A. Parallel emitted silicon nitride nanophotonic phased arrays for two-dimensional beam steering. OPTICS LETTERS 2021; 46:5699-5702. [PMID: 34780440 DOI: 10.1364/ol.443414] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 10/23/2021] [Indexed: 05/25/2023]
Abstract
In this Letter, a two-dimensional (2D) beam steering on silicon nitride (SiNx) nanophotonic phased arrays from visible to near-infrared wavelengths is reported for the first time, to the best of our knowledge. In order to implement beam steering along the transverse direction for one-dimensional waveguide surface grating arrays, wavelengths from 650 to 980 nm provided by the supercontinuum laser are used to excite the phased array. Then the beams are parallel radiated with steering angles in a sequence of 26.84° to -16.54∘ along the transverse direction, and a continuous line in the far field consisting of parallel emitted spots is produced with a total view angle of 43.38°. Moreover, this continuous far-field line is steered along the longitudinal direction with massive wavelengths simultaneously tuned by phase shifts from -π/2 to over +π/2. This method with massive parallel wavelengths emitted paves a new way for 2D steering on SiNx nanophotonic phased arrays.
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14
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Tagkoudi E, Amiot CG, Genty G, Brès CS. Extreme polarization-dependent supercontinuum generation in an uncladded silicon nitride waveguide. OPTICS EXPRESS 2021; 29:21348-21357. [PMID: 34265924 DOI: 10.1364/oe.430197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 06/10/2021] [Indexed: 06/13/2023]
Abstract
We experimentally demonstrate the generation of a short-wave infrared supercontinuum in an uncladded silicon nitride (Si3N4) waveguide with extreme polarization sensitivity at the pumping wavelength of 2.1 µm. The air-clad waveguide is specifically designed to yield anomalous dispersion regime for transverse electric (TE) mode excitation and all-normal-dispersion (ANDi) at near-infrared wavelengths for the transverse magnetic (TM) mode. Dispersion engineering of the polarization modes allows for switching via simple adjustment of the input polarization state from an octave-spanning soliton fission-driven supercontinuum with fine spectral structure to a flat and smooth ANDi supercontinuum dominated by a self-phase modulation mechanism (SPM). Such a polarization sensitive supercontinuum source offers versatile applications such as broadband on-chip sensing to pulse compression and few-cycle pulse generation. Our experimental results are in very good agreement with numerical simulations.
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15
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Chen B, Hong L, Hu C, Li Z. White Laser Realized via Synergic Second- and Third-Order Nonlinearities. RESEARCH 2021; 2021:1539730. [PMID: 33842891 PMCID: PMC8014043 DOI: 10.34133/2021/1539730] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 03/01/2021] [Indexed: 12/02/2022]
Abstract
White laser with balanced performance of broad bandwidth, high average and peak power, large pulse energy, high spatial and temporal coherence, controllable spectrum profile, and overall chroma are highly desirable in various fields of modern science. Here, for the first time, we report an innovative scheme of harnessing the synergic action of both the second-order nonlinearity (2nd-NL) and the third-order nonlinearity (3rd-NL) in a single chirped periodically poled lithium niobate (CPPLN) nonlinear photonic crystal driven by a high-peak-power near-infrared (NIR) (central wavelength~1400 nm, energy~100 μJ per pulse) femtosecond pump laser to produce visible to near infrared (vis-NIR, 400-900 nm) supercontinuum white laser. The CPPLN involves a series of reciprocal-lattice bands that can be exploited to support quasiphase matching for simultaneous broadband second- and third-harmonic generations (SHG and THG) with considerable conversion efficiency. Due to the remarkable 3rd-NL which is due to the high energy density of the pump, SHG and THG laser pulses will induce significant spectral broadening in them and eventually generate bright vis-NIR white laser with high conversion efficiency up to 30%. Moreover, the spectral profile and overall chroma of output white laser can be widely modulated by adjusting the pump laser intensity, wavelength, and polarization. Our work indicates that one can deeply engineer the synergic and collective action of 2nd-NL and 3rd-NL in nonlinear crystals to accomplish high peak power, ultrabroadband vis-NIR white laser and hopefully realize the even greater but much more challenging dream of ultraviolet-visible-infrared full-spectrum laser.
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Affiliation(s)
- Baoqin Chen
- School of Physics and Optoelectronics, South China University of Technology, Guangzhou 510641, China
| | - Lihong Hong
- School of Physics and Optoelectronics, South China University of Technology, Guangzhou 510641, China
| | - Chenyang Hu
- Guangdong Jingqi Laser Technology Corporation Limited, Songshanhu, Dongguan 523808, China
| | - Zhiyuan Li
- School of Physics and Optoelectronics, South China University of Technology, Guangzhou 510641, China
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16
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Higher order mode supercontinuum generation in tantalum pentoxide (Ta 2O 5) channel waveguide. Sci Rep 2021; 11:7978. [PMID: 33846403 PMCID: PMC8042067 DOI: 10.1038/s41598-021-86922-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 03/18/2021] [Indexed: 11/08/2022] Open
Abstract
We fabricated tantalum pentoxide (Ta2O5) channel waveguides and used them to experimentally demonstrate higher-order mode supercontinuum (SC) generation. The Ta2O5 waveguide has a high nonlinear refractive index which was in an order magnitude of 10-14 cm2/W and was designed to be anomalously dispersive at the pumping wavelength. To the best of our knowledge, this is the first time a higher-order mode femtosecond pump based broadband SC has been measured from a nonlinear waveguide using the phase-matching method. This enabled us to demonstrate a SC spectrum spanning from 842 to 1462 nm (at - 30 dB), which corresponds to 0.83 octaves, when using the TM10 waveguide mode. When using the TE10 mode, the SC bandwidth is slightly reduced for the same excitation peak power. In addition, we theoretically estimated and discussed the possibility of using the broadband higher-order modes emitted from the Ta2O5 waveguide for trapping nanoparticles. Hence, we believe that demonstrated Ta2O5 waveguide are a promising broadband light source for optical applications such as frequency metrology, Raman spectroscopy, molecular spectroscopy and optical coherence tomography.
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17
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CORNERSTONE’s Silicon Photonics Rapid Prototyping Platforms: Current Status and Future Outlook. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10228201] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The field of silicon photonics has experienced widespread adoption in the datacoms industry over the past decade, with a plethora of other applications emerging more recently such as light detection and ranging (LIDAR), sensing, quantum photonics, programmable photonics and artificial intelligence. As a result of this, many commercial complementary metal oxide semiconductor (CMOS) foundries have developed open access silicon photonics process lines, enabling the mass production of silicon photonics systems. On the other side of the spectrum, several research labs, typically within universities, have opened up their facilities for small scale prototyping, commonly exploiting e-beam lithography for wafer patterning. Within this ecosystem, there remains a challenge for early stage researchers to progress their novel and innovate designs from the research lab to the commercial foundries because of the lack of compatibility of the processing technologies (e-beam lithography is not an industry tool). The CORNERSTONE rapid-prototyping capability bridges this gap between research and industry by providing a rapid prototyping fabrication line based on deep-UV lithography to enable seamless scaling up of production volumes, whilst also retaining the ability for device level innovation, crucial for researchers, by offering flexibility in its process flows. This review article presents a summary of the current CORNERSTONE capabilities and an outlook for the future.
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Lu J, Liu X, Bruch AW, Zhang L, Wang J, Yan J, Tang HX. Ultraviolet to mid-infrared supercontinuum generation in single-crystalline aluminum nitride waveguides. OPTICS LETTERS 2020; 45:4499-4502. [PMID: 32796993 DOI: 10.1364/ol.398257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 07/06/2020] [Indexed: 06/11/2023]
Abstract
We demonstrate ultrabroadband supercontinuum generation from ultraviolet to mid-infrared wavelengths in single-crystalline aluminum nitride waveguides. Tunable dispersive waves are observed at the mid-infrared regime by precisely controlling the waveguide widths. In addition, ultraviolet light is generated through cascaded second-harmonic generation in the modal phase-matched waveguides. Numerical simulation indicates a high degree of coherence of the generated spectrum at around the telecom pump and two dispersive waves. Our results establish a reliable path for multiple octave supercontinuum comb generation in single-crystalline aluminum nitride to enable applications including precision frequency metrology and spectroscopy.
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19
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Karim MR, Al Kayed N, Rabiul Hossain M, Rahman BMA. Study of low-peak-power highly coherent broadband supercontinuum generation through a dispersion-engineered Si-rich silicon nitride waveguide. APPLIED OPTICS 2020; 59:5948-5956. [PMID: 32672738 DOI: 10.1364/ao.395705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/07/2020] [Indexed: 06/11/2023]
Abstract
Since the first observation by Alfano and Shapiro in the 1970s [Phys. Rev. Lett.24, 584 (1970)PRLTAO0031-900710.1103/PhysRevLett.24.584], supercontinuum generation study has become an attractive research area in the field of broadband light source design, including its use in various applications associated with nonlinear optics in recent years. In this work, the numerical demonstration of ultrabroadband supercontinuum generation in the mid-infrared (MIR) region via the use of complementary metal-oxide semiconductor compatible Si-rich silicon nitride as the core in a planar waveguide design employing one of two materials, either LiNbO3 or MgF2 glass, as the top and bottom claddings is explored. A rigorous numerical investigation of broadband source design in the MIR using 2 mm long Si-rich silicon nitride waveguides is carried out in terms of waveguide structural parameter variations, input peak power variation, varying unexpected deformation of the waveguide along the core region during fabrication, and spectral coherence analysis. Among the several waveguide models studied, two promising designs are identified for wideband supercontinuum generation up to the MIR using a relatively low input peak power of 50 W. Simulation results reveal that spectral coverage spanning from 0.8 µm to 4.6 µm can be obtained by using a LiNbO3-cladded waveguide, and similar spectral coverage is also predicted for the other design, a MgF2-cladded waveguide. To the best of our knowledge, this is the widest spectral span in the MIR region employing a Si-rich silicon nitride waveguide so far. In dispersion tuning as well as in supercontinuum generation, the effect of possible unexpected waveguide deformation along the transverse directions during fabrication is also studied. No significant amount of spectral change is observed in the proposed model for a maximum of 10° inside/outside variation along the width. On the other hand, even 1° upward/downward variation along the thickness could cause substantial spectral change at the waveguide output. Finally, the obtained output spectra from the proposed waveguides are found to be highly coherent and can be applied in various MIR region applications such as optical coherence tomography, spectroscopic measurement, and frequency metrology.
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Abstract
In this paper, integration of silicon oxycarbide (SiOC) and silicon nitride (Si3N4) platforms was demonstrated to realize ultra-efficient thermal tuning of photonic integrated circuits. Si3N4 being a fascinating photonic material with moderate refractive index (n ≈ 2) and ultra-low loss, lacks thermo-optic coefficient that makes thermal phase actuators long and dissipate high powers. Integration of SiOC coating with a comparable refractive index (n = 2.2) boosts the effective thermo-optic efficiency of Si3N4 photonic circuits by almost an order of magnitude with no additional loss. An SiOC layer was deposited by the reactive RF magnetron sputtering technique from the SiC target at room temperature. The structural, chemical and optical characterizations of the sputter deposited SiOC layer were performed with SEM, AFM, EDS and spectroscopic ellipsometry. The results of SiOC-coated Si3N4 and pristine Si3N4 photonic devices were discussed and compared. SiOC was demonstrated as an enabling platform for low-loss and power-efficient thermal phase actuators in conventional photonic technologies with application in reconfigurable photonic systems.
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21
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Mohanty A, Li Q, Tadayon MA, Roberts SP, Bhatt GR, Shim E, Ji X, Cardenas J, Miller SA, Kepecs A, Lipson M. Reconfigurable nanophotonic silicon probes for sub-millisecond deep-brain optical stimulation. Nat Biomed Eng 2020; 4:223-231. [PMID: 32051578 DOI: 10.1038/s41551-020-0516-y] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 01/13/2020] [Indexed: 11/09/2022]
Abstract
The use of nanophotonics to rapidly and precisely reconfigure light beams for the optical stimulation of neurons in vivo has remained elusive. Here we report the design and fabrication of an implantable silicon-based probe that can switch and route multiple optical beams to stimulate identified sets of neurons across cortical layers and simultaneously record the produced spike patterns. Each switch in the device consists of a silicon nitride waveguide structure that can be rapidly (<20 μs) reconfigured by electrically tuning the phase of light. By using an eight-beam probe, we show in anaesthetized mice that small groups of single neurons can be independently stimulated to produce multineuron spike patterns at sub-millisecond precision. We also show that a probe integrating co-fabricated electrical recording sites can simultaneously optically stimulate and electrically measure deep-brain neural activity. The technology is scalable, and it allows for beam focusing and steering and for structured illumination via beam shaping. The high-bandwidth optical-stimulation capacity of the device might facilitate the probing of the spatiotemporal neural codes underlying behaviour.
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Affiliation(s)
- Aseema Mohanty
- Department of Electrical Engineering, Columbia University, New York, NY, USA.,School of Electrical and Computer Engineering, Cornell University, Ithaca, NY, USA
| | - Qian Li
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, USA.,Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, USA
| | | | - Samantha P Roberts
- Department of Electrical Engineering, Columbia University, New York, NY, USA
| | - Gaurang R Bhatt
- Department of Electrical Engineering, Columbia University, New York, NY, USA
| | - Euijae Shim
- Department of Electrical Engineering, Columbia University, New York, NY, USA
| | - Xingchen Ji
- Department of Electrical Engineering, Columbia University, New York, NY, USA.,School of Electrical and Computer Engineering, Cornell University, Ithaca, NY, USA
| | - Jaime Cardenas
- Department of Electrical Engineering, Columbia University, New York, NY, USA.,Institute of Optics, University of Rochester, Rochester, NY, USA
| | - Steven A Miller
- Department of Electrical Engineering, Columbia University, New York, NY, USA
| | - Adam Kepecs
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, USA. .,Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, USA. .,Department of Psychiatry, Washington University in St. Louis, St. Louis, MO, USA.
| | - Michal Lipson
- Department of Electrical Engineering, Columbia University, New York, NY, USA.
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22
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Shams-Ansari A, Latawiec P, Okawachi Y, Venkataraman V, Yu M, Desiatov B, Atikian H, Harris GL, Picqué N, Gaeta AL, Lončar M. Supercontinuum generation in angle-etched diamond waveguides. OPTICS LETTERS 2019; 44:4056-4059. [PMID: 31415546 DOI: 10.1364/ol.44.004056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 07/16/2019] [Indexed: 06/10/2023]
Abstract
We experimentally demonstrate on-chip supercontinuum generation in the visible region in angle-etched diamond waveguides. We measure an output spectrum spanning 670-920 nm in a 5-mm-long waveguide using 100-fs pulses with 187 pJ of incident pulse energy. Our fabrication technique, combined with diamond's broad transparency window, offers a potential route toward broadband supercontinuum generation in the UV domain.
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23
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Fan R, Wu CL, Lin YY, Liu CY, Hwang PS, Liu CW, Qiao J, Shih MH, Hung YJ, Chiu YJ, Chu AK, Lee CK. Visible to near-infrared octave spanning supercontinuum generation in tantalum pentoxide (Ta 2O 5) air-cladding waveguide. OPTICS LETTERS 2019; 44:1512-1515. [PMID: 30874689 DOI: 10.1364/ol.44.001512] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 02/21/2019] [Indexed: 06/09/2023]
Abstract
In this work, for the first time, to the best of our knowledge, an anomalous dispersion CMOS-compatible Ta2O5 waveguide was realized, and broadband on-chip supercontinuum generation (SCG) was accordingly demonstrated. When pumped at a center wavelength of 1056 nm with pulses of 100 fs duration and peak power of 396 W, a supercontinuum ranging from 585 nm to 1697 nm was generated, comprising a bandwidth of more than 1.5 octaves and leading to an efficient SCG source. The excellent performance for Ta2O5 to generate SCG benefits mainly from its high nonlinear refractive index, which enhances the efficiency of the nonlinear conversion process.
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Physical origin of higher-order soliton fission in nanophotonic semiconductor waveguides. Sci Rep 2018; 8:17177. [PMID: 30464320 PMCID: PMC6249288 DOI: 10.1038/s41598-018-34344-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 10/09/2018] [Indexed: 11/23/2022] Open
Abstract
Supercontinuum generation in Kerr media has become a staple of nonlinear optics. It has been celebrated for advancing the understanding of soliton propagation as well as its many applications in a broad range of fields. Coherent spectral broadening of laser light is now commonly performed in laboratories and used in commercial “white light” sources. The prospect of miniaturizing the technology is currently driving experiments in different integrated platforms such as semiconductor on insulator waveguides. Central to the spectral broadening is the concept of higher-order soliton fission. While widely accepted in silica fibers, the dynamics of soliton decay in semiconductor waveguides is yet poorly understood. In particular, the role of nonlinear loss and free carriers, absent in silica, remains an open question. Here, through experiments and simulations, we show that nonlinear loss is the dominant perturbation in wire waveguides, while free-carrier dispersion is dominant in photonic crystal waveguides.
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25
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Magden ES, Li N, Raval M, Poulton CV, Ruocco A, Singh N, Vermeulen D, Ippen EP, Kolodziejski LA, Watts MR. Transmissive silicon photonic dichroic filters with spectrally selective waveguides. Nat Commun 2018; 9:3009. [PMID: 30068975 PMCID: PMC6070617 DOI: 10.1038/s41467-018-05287-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 06/16/2018] [Indexed: 11/08/2022] Open
Abstract
Many optical systems require broadband filters with sharp roll-offs for efficiently splitting or combining light across wide spectra. While free space dichroic filters can provide broadband selectivity, on-chip integration of these high-performance filters is crucial for the scalability of photonic applications in multi-octave interferometry, spectroscopy, and wideband wavelength-division multiplexing. Here we present the theory, design, and experimental characterization of integrated, transmissive, 1 × 2 port dichroic filters using spectrally selective waveguides. Mode evolution through adiabatic transitions in the demonstrated filters allows for single cutoff and flat-top responses with low insertion losses and octave-wide simulated bandwidths. Filters with cutoffs around 1550 and 2100 nm are fabricated on a silicon-on-insulator platform with standard complementary metal-oxide-semiconductor processes. A filter roll-off of 2.82 dB nm-1 is achieved while maintaining ultra-broadband operation. This new class of nanophotonic dichroic filters can lead to new paradigms in on-chip communications, sensing, imaging, optical synthesis, and display applications.
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Affiliation(s)
- Emir Salih Magden
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
- Department of Electrical and Electronics Engineering, Koç University, Rumelifeneri Yolu, Sariyer, 34450, Istanbul, Turkey.
| | - Nanxi Li
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
- John A. Paulson School of Engineering and Applied Science, Harvard University, 29 Oxford Street, Cambridge, MA, 02138, USA
| | - Manan Raval
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Christopher V Poulton
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
- Analog Photonics, One Marina Park Drive, Boston, MA, 02210, USA
| | - Alfonso Ruocco
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
- Cambridge Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge, CB3 0FA, UK
| | - Neetesh Singh
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Diedrik Vermeulen
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
- Analog Photonics, One Marina Park Drive, Boston, MA, 02210, USA
| | - Erich P Ippen
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Leslie A Kolodziejski
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Michael R Watts
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
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Varytis P, Huynh DN, Hartmann W, Pernice W, Busch K. Design study of random spectrometers for applications at optical frequencies. OPTICS LETTERS 2018; 43:3180-3183. [PMID: 29957811 DOI: 10.1364/ol.43.003180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 06/05/2018] [Indexed: 06/08/2023]
Abstract
Compact spectrometers based on disordered planar waveguides exhibit a rather high resolution with a relatively small footprint compared to conventional spectrometers. This is achieved by multiple scattering of light, which-if properly engineered-significantly enhances the effective optical path length. Here a design study of random spectrometers for TE- and TM-polarized light is presented that combines the results of Mie theory, multiple-scattering theory, and full electromagnetic simulations. It is shown that the performance of such random spectrometers depends on single-scattering quantities, notably on the overall scattering efficiency and the asymmetry parameter. Further, the study shows that a well-developed diffusive regime is not required in practice and that a standard integrated-optical layout is sufficient to obtain efficient devices even for rather weakly scattering systems consisting of low index inclusions in high-index matrices, such as pores in planar silicon-nitride-based waveguides. This allows for both significant reductions in footprint with acceptable losses in resolution and for device operation in the visible and near-infrared frequency range.
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27
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Feigel B, Castelló-Lurbe D, Thienpont H, Vermeulen N. Opportunities for visible supercontinuum light generation in integrated diamond waveguides. OPTICS LETTERS 2017; 42:3804-3807. [PMID: 28957133 DOI: 10.1364/ol.42.003804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 08/26/2017] [Indexed: 06/07/2023]
Abstract
We numerically show the advantages of using diamond-on-insulator (DOI) waveguides to design compact supercontinuum (SC) light sources for the visible (VIS) wavelength range. We conclude that the DOI platform is more suitable than silicon nitride waveguides for tailoring the dispersion in such a way that a zero-dispersion wavelength (ZDW) is obtained in the VIS, as is required to achieve efficient VIS SC generation (SCG). After designing a DOI waveguide that features a ZDW at ∼600 nm, we exploit it to numerically obtain a smooth SC ranging from 453 nm to 1030 nm above the -30 dB point after propagation over 4 mm. Our result extends beyond the state-of-the-art shortest VIS wavelengths induced by SCG in integrated waveguides, while using ∼26 times lower input energy and a shorter waveguide length, thus showcasing the potential of the DOI platform for on-chip VIS SC light sources.
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28
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Dorche AE, Abdollahramezani S, Taheri H, Eftekhar AA, Adibi A. Extending chip-based Kerr-comb to visible spectrum by dispersive wave engineering. OPTICS EXPRESS 2017; 25:22362-22374. [PMID: 29041548 DOI: 10.1364/oe.25.022362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 08/21/2017] [Indexed: 06/07/2023]
Abstract
Anomalous group velocity dispersion is a key parameter for generating bright solitons, and thus wideband Kerr frequency combs. Extension of the frequency combs spectrum to visible wavelengths has been a major challenge because of the strong normal dispersion of conventional photonic materials at these wavelengths. In this paper, we numerically demonstrate a wideband frequency comb extending from near-infrared to visible wavelengths (∼1200 nm to 650 nm). The proposed frequency comb micro-resonator takes advantage of a wideband blue-shifted anomalous dispersion, achieved in an optimized over-etched silicon nitride waveguide and strong power transfer to shorter wavelengths through radiative dispersive waves, achieved by modulating the dispersion in a coupled resonator architecture. We show the possibility of obtaining a close to visible dispersive Cherenkov radiation peak that is only 10 dB below the overall comb peak and can be tuned by adjusting the coupling structure in the coupled resonator architecture.
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29
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Silicon Nitride Photonic Integration Platforms for Visible, Near-Infrared and Mid-Infrared Applications. SENSORS 2017; 17:s17092088. [PMID: 28895906 PMCID: PMC5620990 DOI: 10.3390/s17092088] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 08/31/2017] [Accepted: 09/06/2017] [Indexed: 11/17/2022]
Abstract
Silicon nitride photonics is on the rise owing to the broadband nature of the material, allowing applications of biophotonics, tele/datacom, optical signal processing and sensing, from visible, through near to mid-infrared wavelengths. In this paper, a review of the state of the art of silicon nitride strip waveguide platforms is provided, alongside the experimental results on the development of a versatile 300 nm guiding film height silicon nitride platform.
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30
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He L, Guo Y, Han Z, Wada K, Kimerling LC, Michel J, Agarwal AM, Li G, Zhang L. Loss reduction of silicon-on-insulator waveguides for deep mid-infrared applications. OPTICS LETTERS 2017; 42:3454-3457. [PMID: 28957061 DOI: 10.1364/ol.42.003454] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 08/04/2017] [Indexed: 06/07/2023]
Abstract
We report that propagation loss of optical waveguides based on a silicon-on-insulator (SOI) material platform can be greatly reduced. Our simulations show that the loss, including SiO2 absorption and substrate leakage, but no scattering loss, is 0.024 and 0.53 dB/cm in the deep mid-infrared at 4.8 and 7.1 μm wavelengths, where the material absorption in SiO2 is 100 and 1000 dB/cm, respectively. The loss becomes negligible, compared to scattering loss in Si waveguides. This is enabled by using the TE10 mode in a pedestal waveguide. We also show that the TE10 mode can be excited in the proposed waveguide by the fundamental mode with a coupling efficiency of >94%. Low propagation loss, high coupling efficiency, and fabrication-friendly design would make it promising for practical use of SOI devices in the deep mid-infrared.
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31
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Carlson DR, Hickstein DD, Lind A, Droste S, Westly D, Nader N, Coddington I, Newbury NR, Srinivasan K, Diddams SA, Papp SB. Self-referenced frequency combs using high-efficiency silicon-nitride waveguides. OPTICS LETTERS 2017; 42:2314-2317. [PMID: 28614340 DOI: 10.1364/ol.42.002314] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 05/17/2017] [Indexed: 06/07/2023]
Abstract
We utilize silicon-nitride waveguides to self-reference a telecom-wavelength fiber frequency comb through supercontinuum generation, using 11.3 mW of optical power incident on the chip. This is approximately 10 times lower than conventional approaches using nonlinear fibers and is enabled by low-loss (<2 dB) input coupling and the high nonlinearity of silicon nitride, which can provide two octaves of spectral broadening with incident energies of only 110 pJ. Following supercontinuum generation, self-referencing is accomplished by mixing 780-nm dispersive-wave light with the frequency-doubled output of the fiber laser. In addition, at higher optical powers, we demonstrate f-to-3f self-referencing directly from the waveguide output by the interference of simultaneous supercontinuum and third harmonic generation, without the use of an external doubling crystal or interferometer. These hybrid comb systems combine the performance of fiber-laser frequency combs with the high nonlinearity and compactness of photonic waveguides, and should lead to low-cost, fully stabilized frequency combs for portable and space-borne applications.
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Dhakal A, Wuytens P, Raza A, Le Thomas N, Baets R. Silicon Nitride Background in Nanophotonic Waveguide Enhanced Raman Spectroscopy. MATERIALS 2017; 10:ma10020140. [PMID: 28772499 PMCID: PMC5459205 DOI: 10.3390/ma10020140] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 02/01/2017] [Accepted: 02/04/2017] [Indexed: 11/16/2022]
Abstract
Recent studies have shown that evanescent Raman spectroscopy using a silicon nitride (SiN) nanophotonic waveguide platform has higher signal enhancement when compared to free-space systems. However, signal-to-noise ratio from the waveguide at a low analyte concentration is constrained by the shot-noise from the background light originating from the waveguide itself. Hence, understanding the origin and properties of this waveguide background luminescence (WGBL) is essential to developing mitigation strategies. Here, we identify the dominating component of the WGBL spectrum composed of a broad Raman scattering due to momentum selection-rule breaking in amorphous materials, and several peaks specific to molecules embedded in the core. We determine the maximum of the Raman scattering efficiency of the WGBL at room temperature for 785 nm excitation to be 4.5 ± 1 × 10−9 cm−1·sr−1, at a Stokes shift of 200 cm−1. This efficiency decreases monotonically for higher Stokes shifts. Additionally, we also demonstrate the use of slotted waveguides and quasi-transverse magnetic polarization as some mitigation strategies.
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Affiliation(s)
- Ashim Dhakal
- Photonics Research Group, INTEC Department, Ghent University/IMEC, Gent 9000, Belgium.
- Center for Nano- and Biophotonics, Ghent University, Gent 9000, Belgium.
- Phutung Research Institute, Balaju-16, Kathmandu 44611, Nepal.
| | - Pieter Wuytens
- Photonics Research Group, INTEC Department, Ghent University/IMEC, Gent 9000, Belgium.
- Center for Nano- and Biophotonics, Ghent University, Gent 9000, Belgium.
- Department of Molecular Biotechnology, Ghent University, Gent 9000, Belgium.
| | - Ali Raza
- Photonics Research Group, INTEC Department, Ghent University/IMEC, Gent 9000, Belgium.
- Center for Nano- and Biophotonics, Ghent University, Gent 9000, Belgium.
| | - Nicolas Le Thomas
- Photonics Research Group, INTEC Department, Ghent University/IMEC, Gent 9000, Belgium.
- Center for Nano- and Biophotonics, Ghent University, Gent 9000, Belgium.
| | - Roel Baets
- Photonics Research Group, INTEC Department, Ghent University/IMEC, Gent 9000, Belgium.
- Center for Nano- and Biophotonics, Ghent University, Gent 9000, Belgium.
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Porcel MAG, Schepers F, Epping JP, Hellwig T, Hoekman M, Heideman RG, van der Slot PJM, Lee CJ, Schmidt R, Bratschitsch R, Fallnich C, Boller KJ. Two-octave spanning supercontinuum generation in stoichiometric silicon nitride waveguides pumped at telecom wavelengths. OPTICS EXPRESS 2017; 25:1542-1554. [PMID: 28158036 DOI: 10.1364/oe.25.001542] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We demonstrate supercontinuum generation in stoichiometric silicon nitride (Si3N4 in SiO2) integrated optical waveguides, pumped at telecommunication wavelengths. The pump laser is a mode-locked erbium fiber laser at a wavelength of 1.56 µm with a pulse duration of 120 fs. With a waveguide-internal pulse energy of 1.4 nJ and a waveguide with 1.0 µm × 0.9 µm cross section, designed for anomalous dispersion across the 1500 nm telecommunication range, the output spectrum extends from the visible, at around 526 nm, up to the mid-infrared, at least to 2.6 µm, the instrumental limit of our detection. This output spans more than 2.2 octaves (454 THz at the -30 dB level). The measured output spectra agree well with theoretical modeling based on the generalized nonlinear Schrödinger equation. The infrared part of the supercontinuum spectra shifts progressively towards the mid-infrared, well beyond 2.6 µm, by increasing the width of the waveguides.
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Yoon Oh D, Yang KY, Fredrick C, Ycas G, Diddams SA, Vahala KJ. Coherent ultra-violet to near-infrared generation in silica ridge waveguides. Nat Commun 2017; 8:13922. [PMID: 28067233 PMCID: PMC5227738 DOI: 10.1038/ncomms13922] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 11/11/2016] [Indexed: 11/25/2022] Open
Abstract
Short duration, intense pulses of light can experience dramatic spectral broadening when propagating through lengths of optical fibre. This continuum generation process is caused by a combination of nonlinear optical effects including the formation of dispersive waves. Optical analogues of Cherenkov radiation, these waves allow a pulse to radiate power into a distant spectral region. In this work, efficient and coherent dispersive wave generation of visible to ultraviolet light is demonstrated in silica waveguides on a silicon chip. Unlike fibre broadeners, the arrays provide a wide range of emission wavelength choices on a single, compact chip. This new capability is used to simplify offset frequency measurements of a mode-locked frequency comb. The arrays can also enable mode-locked lasers to attain unprecedented tunable spectral reach for spectroscopy, bioimaging, tomography and metrology. Continuum generation in optical fibres has enabled many applications, like optical frequency combs. Here, Oh et al. demonstrate controlled dispersive-wave generation in on-chip silica waveguides, which could have a similar impact on integrated devices.
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Affiliation(s)
- Dong Yoon Oh
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, California 91125, USA
| | - Ki Youl Yang
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, California 91125, USA
| | - Connor Fredrick
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Gabriel Ycas
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Scott A Diddams
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Kerry J Vahala
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, California 91125, USA
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35
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Chen Y, Halir R, Molina-Fernández Í, Cheben P, He JJ. High-efficiency apodized-imaging chip-fiber grating coupler for silicon nitride waveguides. OPTICS LETTERS 2016; 41:5059-5062. [PMID: 27805685 DOI: 10.1364/ol.41.005059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Chip-fiber grating couplers have been widely used in silicon-on-insulator platforms. In silicon nitride waveguides, the lower index contrast yields gratings with a weaker radiation strength and poor directionality, thereby limiting the coupling efficiency. Here we propose and design an apodized self-imaging grating coupler in silicon nitride that images an in-plane waveguide input to an output optical fiber placed at a specific distance above the chip. Both amplitude and phase apodizations are employed to engineer the transfer function of the self-imaging grating to produce an image field matching the fiber mode profile. Two-step etch staircase grating teeth are used to achieve directionality as high as 93%. Full three-dimensional finite-difference time-domain simulations show coupling from a 40 μm×40 μm grating to an SMF-28 single mode fiber with a record calculated efficiency of 86% (0.66 dB loss) and a 3 dB bandwidth of 40 nm near the 1550 nm wavelength.
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36
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Okawachi Y, Yu M, Luke K, Carvalho DO, Lipson M, Gaeta AL. Quantum random number generator using a microresonator-based Kerr oscillator. OPTICS LETTERS 2016; 41:4194-4197. [PMID: 27628355 DOI: 10.1364/ol.41.004194] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We demonstrate an all-optical quantum random number generator using a dual-pumped degenerate optical parametric oscillator in a silicon nitride microresonator. The frequency-degenerate bi-phase state output is realized using parametric four-wave mixing in the normal group-velocity dispersion regime with two nondegenerate pumps. We achieve a random number generation rate of 2 MHz and verify the randomness of our output using the National Institute of Standards and Technology Statistical Test Suite. The scheme offers potential for a chip-scale random number generator with gigahertz generation rates and no postprocessing.
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37
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Visible to near-infrared supercontinuum generation in yttrium orthosilicate bulk crystal and ion implanted planar waveguide. Sci Rep 2016; 6:31612. [PMID: 27527662 PMCID: PMC4985816 DOI: 10.1038/srep31612] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 07/25/2016] [Indexed: 12/16/2022] Open
Abstract
This paper reports on the supercontinuum generation in yttrium orthosilicate bulk crystal and 6-mm-long ion implanted planar waveguide. The waveguide is fabricated by 6 MeV oxygen ions implantation with fluence of 5 × 1014 ions/cm2 at room temperature. The yttrium orthosilicate bulk crystal and waveguide are pumped using a mode-locked Ti:Sapphire laser with a center wavelength of 800 nm. The generated broadest supercontinuum spans 720 nm (at −30 dB points) from 380 to 1100 nm in bulk crystal and 510 nm (at −30 dB points) from 490 to 1000 nm in ion implanted waveguide, respectively. Compared to the bulk crystal, the ion implanted waveguide requires almost three orders of magnitude lower pump power to achieve a similar level of broadening. The supercontinuum is generated in the normal dispersion regime and exhibits a relatively smooth spectral shape. Our research findings indicate that ion implantation is an efficient method to produce waveguide in yttrium orthosilicate crystal for low-threshold supercontinuum generation.
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38
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Dhakal A, Peyskens F, Clemmen S, Raza A, Wuytens P, Zhao H, Le Thomas N, Baets R. Single mode waveguide platform for spontaneous and surface-enhanced on-chip Raman spectroscopy. Interface Focus 2016; 6:20160015. [PMID: 27499842 PMCID: PMC4918833 DOI: 10.1098/rsfs.2016.0015] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We review an on-chip approach for spontaneous Raman spectroscopy and surface-enhanced Raman spectroscopy based on evanescent excitation of the analyte as well as evanescent collection of the Raman signal using complementary metal oxide semiconductor (CMOS)-compatible single mode waveguides. The signal is either directly collected from the analyte molecules or via plasmonic nanoantennas integrated on top of the waveguides. Flexibility in the design of the geometry of the waveguide, and/or the geometry of the antennas, enables optimization of the collection efficiency. Furthermore, the sensor can be integrated with additional functionality (sources, detectors, spectrometers) on the same chip. In this paper, the basic theoretical concepts are introduced to identify the key design parameters, and some proof-of-concept experimental results are reviewed.
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Affiliation(s)
- Ashim Dhakal
- Department of Information Technology (INTEC), Photonics Research Group, University of Ghent–imec, Ghent, Belgium
- Center for Nano- and Biophotonics, Ghent University, Ghent, Belgium
| | - Frédéric Peyskens
- Department of Information Technology (INTEC), Photonics Research Group, University of Ghent–imec, Ghent, Belgium
- Center for Nano- and Biophotonics, Ghent University, Ghent, Belgium
| | - Stéphane Clemmen
- Department of Information Technology (INTEC), Photonics Research Group, University of Ghent–imec, Ghent, Belgium
- Center for Nano- and Biophotonics, Ghent University, Ghent, Belgium
| | - Ali Raza
- Department of Information Technology (INTEC), Photonics Research Group, University of Ghent–imec, Ghent, Belgium
- Center for Nano- and Biophotonics, Ghent University, Ghent, Belgium
| | - Pieter Wuytens
- Department of Information Technology (INTEC), Photonics Research Group, University of Ghent–imec, Ghent, Belgium
- Center for Nano- and Biophotonics, Ghent University, Ghent, Belgium
- Department of Molecular Biotechnology, Ghent University, Ghent, Belgium
| | - Haolan Zhao
- Department of Information Technology (INTEC), Photonics Research Group, University of Ghent–imec, Ghent, Belgium
- Center for Nano- and Biophotonics, Ghent University, Ghent, Belgium
| | - Nicolas Le Thomas
- Department of Information Technology (INTEC), Photonics Research Group, University of Ghent–imec, Ghent, Belgium
- Center for Nano- and Biophotonics, Ghent University, Ghent, Belgium
| | - Roel Baets
- Department of Information Technology (INTEC), Photonics Research Group, University of Ghent–imec, Ghent, Belgium
- Center for Nano- and Biophotonics, Ghent University, Ghent, Belgium
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39
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Liu X, Pu M, Zhou B, Krückel CJ, Fülöp A, Torres-Company V, Bache M. Octave-spanning supercontinuum generation in a silicon-rich nitride waveguide. OPTICS LETTERS 2016; 41:2719-2722. [PMID: 27304272 DOI: 10.1364/ol.41.002719] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We experimentally show octave-spanning supercontinuum generation in a nonstoichiometric silicon-rich nitride waveguide when pumped by femtosecond pulses from an erbium fiber laser. The pulse energy and bandwidth are comparable to results achieved in stoichiometric silicon nitride waveguides, but our material platform is simpler to manufacture. We also observe wave-breaking supercontinuum generation by using orthogonal pumping in the same waveguide. Additional analysis reveals that the waveguide height is a powerful tuning parameter for generating mid-infrared dispersive waves while keeping the pump in the telecom band.
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40
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Karpov M, Guo H, Kordts A, Brasch V, Pfeiffer MHP, Zervas M, Geiselmann M, Kippenberg TJ. Raman Self-Frequency Shift of Dissipative Kerr Solitons in an Optical Microresonator. PHYSICAL REVIEW LETTERS 2016; 116:103902. [PMID: 27015482 DOI: 10.1103/physrevlett.116.103902] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Indexed: 05/27/2023]
Abstract
The formation of temporal dissipative Kerr solitons in microresonators driven by a continuous-wave laser enables the generation of coherent, broadband, and spectrally smooth optical frequency combs as well as femtosecond pulse sources with compact form factors. Here we report the observation of a Raman-induced soliton self-frequency shift for a microresonator dissipative Kerr soliton also referred to as the frequency-locked Raman soliton. In amorphous silicon nitride microresonator-based single soliton states the Raman effect manifests itself by a spectrum that is sech^{2} in shape and whose center is spectrally redshifted from the continuous wave pump laser. The shift is theoretically described by the first-order shock term of the material's Raman response, and we infer a Raman shock time of ∼20 fs for amorphous silicon nitride. Moreover, we observe that the Raman-induced frequency shift can lead to a cancellation or overcompensation of the soliton recoil caused by the formation of a coherent dispersive wave. The observations are in agreement with numerical simulations based on the Lugiato-Lefever equation with a Raman shock term. Our results contribute to the understanding of Kerr frequency combs in the soliton regime, enable one to substantially improve the accuracy of modeling, and are relevant to the understanding of the fundamental timing jitter of microresonator solitons.
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Affiliation(s)
- Maxim Karpov
- École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Hairun Guo
- École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Arne Kordts
- École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Victor Brasch
- École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Martin H P Pfeiffer
- École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Michail Zervas
- École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Michael Geiselmann
- École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Tobias J Kippenberg
- École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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41
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Kordts A, Pfeiffer MHP, Guo H, Brasch V, Kippenberg TJ. Higher order mode suppression in high-Q anomalous dispersion SiN microresonators for temporal dissipative Kerr soliton formation. OPTICS LETTERS 2016; 41:452-455. [PMID: 26907395 DOI: 10.1364/ol.41.000452] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
High-Q silicon nitride (SiN) microresonators enable optical Kerr frequency comb generation on a photonic chip and have recently been shown to support fully coherent combs based on temporal dissipative Kerr soliton formation. For bright soliton formation, it is necessary to operate SiN waveguides in the multimode regime in order to produce waveguide induced anomalous group velocity dispersion. However, this regime can lead to local disturbances of the dispersion due to avoided crossings caused by coupling between different mode families and, therefore, prevent the soliton formation. Here, we demonstrate that a single-mode "filtering" section inside high-Q resonators enables efficiently suppression of avoided crossings, while preserving high quality factors (Q∼10(6)). We verify the approach by demonstrating single soliton formation in SiN resonators with a filtering section.
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42
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Johnson AR, Mayer AS, Klenner A, Luke K, Lamb ES, Lamont MRE, Joshi C, Okawachi Y, Wise FW, Lipson M, Keller U, Gaeta AL. Octave-spanning coherent supercontinuum generation in a silicon nitride waveguide. OPTICS LETTERS 2015; 40:5117-5120. [PMID: 26512533 DOI: 10.1364/ol.40.005117] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We demonstrate the generation of a supercontinuum spanning more than 1.4 octaves in a silicon nitride waveguide using sub-100-fs pulses at 1 μm generated by either a 53-MHz, diode-pumped ytterbium (Yb) fiber laser or a 1-GHz, Yb:CaAlGdO(4) (Yb:CALGO) laser. Our numerical simulations show that the broadband supercontinuum is fully coherent, and a spectral interference measurement is used to verify that the supercontinuum generated with the Yb:CALGO laser possesses a high degree of coherence over the majority of its spectral bandwidth. This coherent spectrum may be utilized for optical coherence tomography, spectroscopy, and frequency metrology.
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43
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Epping JP, Hellwig T, Hoekman M, Mateman R, Leinse A, Heideman RG, van Rees A, van der Slot PJM, Lee CJ, Fallnich C, Boller KJ. On-chip visible-to-infrared supercontinuum generation with more than 495 THz spectral bandwidth. OPTICS EXPRESS 2015; 23:19596-19604. [PMID: 26367617 DOI: 10.1364/oe.23.019596] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We report ultra-broadband supercontinuum generation in high-confinement Si3N4 integrated optical waveguides. The spectrum extends through the visible (from 470 nm) to the infrared spectral range (2130 nm) comprising a spectral bandwidth wider than 495 THz, which is the widest supercontinuum spectrum generated on a chip.
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