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Hamrouni M, Jankowski M, Hwang AY, Flemens N, Mishra J, Langrock C, Safavi-Naeini AH, Fejer MM, Südmeyer T. Picojoule-level supercontinuum generation in thin-film lithium niobate on sapphire. OPTICS EXPRESS 2024; 32:12004-12011. [PMID: 38571035 DOI: 10.1364/oe.514649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 02/02/2024] [Indexed: 04/05/2024]
Abstract
We demonstrate ultraviolet-to-mid-infrared supercontinuum generation (SCG) inside thin-film lithium niobate (TFLN) on sapphire nanowaveguides. This platform combines wavelength-scale confinement and quasi-phasematched nonlinear interactions with a broad transparency window extending from 350 to 4500 nm. Our approach relies on group-velocity-matched second-harmonic generation, which uses an interplay between saturation and a small phase-mismatch to generate a spectrally broadened fundamental and second harmonic using only a few picojoules of in-coupled fundamental pulse energies. As the on-chip pulse energy is increased to tens of picojoules, these nanowaveguides generate harmonics up to the fifth order by a cascade of sum-frequency mixing processes. For in-coupled pulse energies in excess of 25 picojoules, these harmonics merge together to form a supercontinuum spanning 360-2660 nm. We use the overlap between the first two harmonic spectra to detect f-2f beatnotes of the driving laser directly at the waveguide output, which verifies the coherence of the generated harmonics. These results establish TFLN-on-sapphire as a viable platform for generating ultra-broadband coherent light spanning from the ultraviolet to mid-infrared spectral regions.
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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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3
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Zhou J, Kang R, Cheng P, Liu Z, Zhao J, Zuo Z. Simulation on a dispersion-managed 4H-SiC on insulator waveguide for infrared supercontinuum generation. APPLIED OPTICS 2023; 62:34-38. [PMID: 36606846 DOI: 10.1364/ao.476706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
We demonstrate infrared supercontinuum generation in 4H-SiC on insulator slab waveguides. The effect of waveguide geometry parameters on dispersion is investigated to switch the zero-dispersion wavelength close to the pump wavelength. The 1 cm long 4H-SiC waveguide is pumped by 100 fs pulses at 1550 nm with 2000 W peak power, and the generated supercontinuum extends from ∼1000 to ∼3560n m (at 20 dB level). This work shows that 4H-SiC has significant potential as on-chip photonic sources for spectroscopic applications in infrared wavelengths.
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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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Pelgrin V, Wang Y, Peltier J, Alonso-Ramos C, Vivien L, Sun Z, Cassan E. Boosting the SiN nonlinear photonic platform with transition metal dichalcogenide monolayers. OPTICS LETTERS 2022; 47:734-737. [PMID: 35167512 DOI: 10.1364/ol.440462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 12/10/2021] [Indexed: 06/14/2023]
Abstract
In the past few years, we have witnessed increased interest in the use of 2D materials to produce hybrid photonic nonlinear waveguides. Although graphene has attracted most of the attention, other families of 2D materials such as transition metal dichalcogenides have also shown promising nonlinear performance. In this work, we propose a strategy for designing silicon nitride waveguiding structures with embedded MoS2 for nonlinear applications. The transverse geometry of the hybrid waveguide is optimized for high third-order nonlinear effects using optogeometrical engineering and multiple layers of MoS2. Stacking multiple monolayers results in an improvement of two orders of magnitude compared to standard silicon nitride waveguides. The hybrid waveguide performance is then investigated in terms of four-wave mixing enhancement in micro-ring resonator configurations. A signal/idler conversion efficiency of -6.3 dB is reached for a wavelength of around 1.55 µm with a 5 mW pumping level.
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Ishizawa A, Kawashima K, Kou R, Xu X, Tsuchizawa T, Aihara T, Yoshida K, Nishikawa T, Hitachi K, Cong G, Yamamoto N, Yamada K, Oguri K. Direct f-3f self-referencing using an integrated silicon-nitride waveguide. OPTICS EXPRESS 2022; 30:5265-5273. [PMID: 35209493 DOI: 10.1364/oe.449575] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 01/16/2022] [Indexed: 06/14/2023]
Abstract
We have achieved the simultaneous generation of a 2.6-octave-wide supercontinuum (SC) spectrum over 400-2500 nm and third-harmonic light solely by a dispersion-controlled silicon-nitride waveguide (SiNW). To increase the visible intensity of the SC light component, we fabricated low-loss 5-mm-long deuterated SiNWs with spot-size converters by low-temperature deposition. We succeeded in measuring the carrier-envelope-offset (CEO) signal with a 34-dB signal-to-noise ratio because this short deuterated SiNW provides a large temporal overlap between the f and 3f components. In addition, we have demonstrated this method of CEO locking at telecommunications wavelengths with f-3f self-referencing generated solely by the SiNW without the use of highly nonlinear fiber and an additional nonlinear crystal. Compared with the method of CEO locking with a highly nonlinear fiber and a standard f-2f self-referencing interferometer, this method is not only simple and compact but also stable.
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Ji X, Mojahed D, Okawachi Y, Gaeta AL, Hendon CP, Lipson M. Millimeter-scale chip-based supercontinuum generation for optical coherence tomography. SCIENCE ADVANCES 2021; 7:eabg8869. [PMID: 34533990 PMCID: PMC8448444 DOI: 10.1126/sciadv.abg8869] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Supercontinuum sources for optical coherence tomography (OCT) have raised great interest as they provide broad bandwidth to enable high resolution and high power to improve imaging sensitivity. Commercial fiber-based supercontinuum systems require high pump powers to generate broad bandwidth and customized optical filters to shape/attenuate the spectra. They also have limited sensitivity and depth performance. We introduce a supercontinuum platform based on a 1-mm2 Si3N4 photonic chip for OCT. We directly pump and efficiently generate supercontinuum near 1300 nm without any postfiltering. With a 25-pJ pump pulse, we generate a broadband spectrum with a flat 3-dB bandwidth of 105 nm. Integrating the chip into a spectral domain OCT system, we achieve 105-dB sensitivity and 1.81-mm 6-dB sensitivity roll-off with 300-μW optical power on sample. We image breast tissue to demonstrate strong imaging performance. Our chip will pave the way toward portable OCT and incorporating integrated photonics into optical imaging technologies.
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Affiliation(s)
- Xingchen Ji
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
| | - Diana Mojahed
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Yoshitomo Okawachi
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, USA
| | - Alexander L. Gaeta
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, USA
| | - Christine P. Hendon
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
- Corresponding author. (M.L.); (C.P.H.)
| | - Michal Lipson
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
- Corresponding author. (M.L.); (C.P.H.)
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8
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Castelló-Lurbe D. Dispersive-wave self-frequency shift unveiled through length scales propagation. OPTICS LETTERS 2021; 46:4152-4155. [PMID: 34469962 DOI: 10.1364/ol.434304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 07/21/2021] [Indexed: 06/13/2023]
Abstract
Nonlinear propagation of light pulses can excite dispersive waves anchored at frequencies determined by the chromatic dispersion curve. In this work, conditions enabling dispersive-wave self-frequency shift over the propagation distance are analytically derived in the normal dispersion regime. Importantly, this novel, to the best of our knowledge, scenario is not found by solving the complex dynamics of the pulse, but by studying the evolution of the nonlinear and dispersive length scales. This approach allows a simpler, yet consistent and insightful, analysis that may also be very useful in other nonlinear regimes.
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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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10
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Hwang J, Kim DG, Han S, Jeong D, Lee YH, Choi DY, Lee H. Supercontinuum generation in As 2S 3 waveguides fabricated without direct etching. OPTICS LETTERS 2021; 46:2413-2416. [PMID: 33988597 DOI: 10.1364/ol.422606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 04/06/2021] [Indexed: 06/12/2023]
Abstract
We report a supercontinuum generation (SCG) in a waveguide that spontaneously forms without an etching process during the deposition of a core material on a preformed ${\rm{Si}}{{\rm{O}}_2}$ substructure. The mechanism of dispersion control for this new, to the best of our knowledge, type of waveguide is analyzed by numerical simulation, which results in a design rule to achieve a target dispersion profile by adjusting the substructure geometry. SCG is experimentally demonstrated with a waveguide made of ${\rm{A}}{{\rm{s}}_2}{{\rm{S}}_3}$, chalcogenide glass, which has low material absorption over the mid-IR range. A dispersion-controlled waveguide with a length of 10 mm pumped with 77 pJ pulses at a telecommunication wavelength of 1560 nm resulted in a supercontinuum that extends by more than 1.5 octaves.
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11
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Investigation of Side Wall Roughness Effect on Optical Losses in a Multimode Si3N4 Waveguide Formed on a Quartz Substrate. PHOTONICS 2020. [DOI: 10.3390/photonics7040104] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This article presents the results of the study of the influence of the most significant parameters of the side wall roughness of an ultra-thin silicon nitride lightguide layer of multimode integrated optical waveguides with widths of 3 and 8 microns. The choice of the waveguide width was made due to the need to provide multimode operation for telecommunication wavelengths, which is necessary to ensure high integration density. Scattering in waveguide structures was measured by optical frequency domain reflectometry (OFDR) of a backscattering reflectometer. The finite difference time domain method (FDTD) was used to study the effect of roughness parameters on optical losses in fabricated waveguides, the roughness parameters that most strongly affect optical scattering were determined, and methods of its significant reduction were specified. The prospects for implementing such structures on a quartz substrate are justified.
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12
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Yu Q, Gao J, Ye N, Chen B, Sun K, Xie L, Srinivasan K, Zervas M, Navickaite G, Geiselmann M, Beling A. Heterogeneous photodiodes on silicon nitride waveguides. OPTICS EXPRESS 2020; 28:14824-14830. [PMID: 32403516 DOI: 10.1364/oe.387939] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 04/14/2020] [Indexed: 06/11/2023]
Abstract
Heterogeneous integration through low-temperature die bonding is a promising technique to enable high-performance III-V photodetectors on the silicon nitride (Si3N4) photonic platform. Here we demonstrate InGaAs/InP modified uni-traveling carrier photodiodes on Si3N4 waveguides with 20 nA dark current, 20 GHz bandwidth, and record-high external (internal) responsivities of 0.8 A/W (0.94 A/W) and 0.33 A/W (0.83 A/W) at 1550 nm and 1064 nm, respectively. Open eye diagrams at 40 Gbit/s are demonstrated. Balanced photodiodes of this type reach 10 GHz bandwidth with over 40 dB common mode rejection ratio.
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13
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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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Kuyken B, Billet M, Leo F, Yvind K, Pu M. Octave-spanning coherent supercontinuum generation in an AlGaAs-on-insulator waveguide. OPTICS LETTERS 2020; 45:603-606. [PMID: 32004262 DOI: 10.1364/ol.45.000603] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 11/21/2019] [Indexed: 06/10/2023]
Abstract
We demonstrate supercontinuum generation over an octave spaning from 1055 to 2155 nm on the highly nonlinear aluminum gallium arsenide (AlGaAs)-on-insulator platform. This is enabled by the generation of two dispersive waves in a 3-mm-long dispersion-engineered nano-waveguide. The waveguide is pumped at telecom wavelengths (1555 nm) with 3.6 pJ femtosecond pulses. We experimentally validate the coherence of the generated supercontinuum around the pump wavelength (1450-1750 nm), and our numerical simulation shows a high degree of coherence over the full spectrum.
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15
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Carlson DR, Hutchison P, Hickstein DD, Papp SB. Generating few-cycle pulses with integrated nonlinear photonics. OPTICS EXPRESS 2019; 27:37374-37382. [PMID: 31878519 DOI: 10.1364/oe.27.037374] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 11/17/2019] [Indexed: 06/10/2023]
Abstract
Ultrashort laser pulses that last only a few optical cycles have been transformative tools for studying and manipulating light-matter interactions. Few-cycle pulses are typically produced from high-peak-power lasers, either directly from a laser oscillator or through nonlinear effects in bulk or fiber materials. Now, an opportunity exists to explore the few-cycle regime with the emergence of fully integrated nonlinear photonics. Here, we experimentally and numerically demonstrate how lithographically patterned waveguides can be used to generate few-cycle laser pulses from an input seed pulse. Moreover, our work explores a design principle in which lithographically varying the group-velocity dispersion in a waveguide enables the creation of highly constant-intensity supercontinuum spectra across an octave of bandwidth. An integrated source of few-cycle pulses could broaden the range of applications for ultrafast light sources, including supporting new lab-on-a-chip systems in a scalable form factor.
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16
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Singh N, Vermulen D, Ruocco A, Li N, Ippen E, Kärtner FX, Watts MR. Supercontinuum generation in varying dispersion and birefringent silicon waveguide. OPTICS EXPRESS 2019; 27:31698-31712. [PMID: 31684397 DOI: 10.1364/oe.27.031698] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 09/15/2019] [Indexed: 06/10/2023]
Abstract
Ability to selectively enhance the amplitude and maintain high coherence of the supercontinuum signal with long pulses is gaining significance. In this work, an extra degree of freedom afforded by varying the dispersion profile of a waveguide is utilized to selectively enhance supercontinuum. As much as 16 dB signal enhancement in the telecom window and 100 nm of wavelength extension is achieved with a cascaded waveguide, compared to a fixed dispersion waveguide. Waveguide tapering, in particular with increasing width, is determined to have a flatter and more coherent supercontinuum than a fixed dispersion waveguide when longer input pulses are used. Furthermore, due to the strong birefringence of an asymmetric silicon waveguide the supercontinuum signal is broadened by pumping simultaneously with both quasi-transverse electric (TE) and quasi-transverse magnetic (TM) mode in the anomalous dispersion regime. Thus, selective signal generation is obtained by controlling the dispersion for the two modes. Such waveguides offer several advantages over optical fiber as the variation in dispersion can be controlled with greater flexibility in an integrated platform. This work paves the way forward for various applications in fields ranging from medicine to telecom where specific wavelength windows need to be targeted.
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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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18
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Ma J, Sun Y, Chen S. Silicon nitride/titanium oxide hybrid waveguide design enabling broadband athermal operation. APPLIED OPTICS 2019; 58:5267-5272. [PMID: 31503624 DOI: 10.1364/ao.58.005267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 06/05/2019] [Indexed: 06/10/2023]
Abstract
This paper presents a special design of a new kind of silicon nitride/titanium oxide hybrid waveguide with multi-layer materials laminate structure aiming at broadband athermal operation. By incorporating three layers of titanium oxide whose thermo-optic coefficient (TOC) is negative in the waveguide core and upper cladding regions, the thermal drift of the conventional strip waveguide induced by the positive TOC of silicon nitride is fully compensated, with the effective TOC of the hybrid waveguide achieving zero at 1550 nm and only varying extremely slightly within ±6×10-7/K in the wavelength band from 1350 to 1850 nm. In addition, due to the inherent alternate growth manner of titanium dioxide and silicon nitride thin layers, this new kind of multi-layer material laminate structure waveguide holds the potential of avoiding the challenging growth of low-stress crack-free single-layer silicon nitride film thick enough for realizing an anomalous dispersion waveguide. Furthermore, we numerically demonstrate the different influences of the temperature change on optical frequency comb generation between the traditional waveguide and the hybrid waveguide, and we find that the athermal hybrid waveguide is much more temperature insensitive than the strip waveguide.
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19
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Delfyett PJ, Klee A, Bagnell K, Juodawlkis P, Plant J, Zaman A. Exploring the limits of semiconductor-laser-based optical frequency combs. APPLIED OPTICS 2019; 58:D39-D49. [PMID: 31044819 DOI: 10.1364/ao.58.000d39] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 02/19/2019] [Indexed: 06/09/2023]
Abstract
We report a study on the performance limits of stabilized optical frequency combs from semiconductor mode-locked diode lasers. Operating characteristics such as the number of comb lines, comb tooth linewidth, the physical parameters that affect the independent control of pulse repetition rate and offset frequency, and the potential for self-stabilization, are explored.
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20
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Mia MB, Jaidye N, Kim S. Extremely high dispersions in heterogeneously coupled waveguides. OPTICS EXPRESS 2019; 27:10426-10437. [PMID: 31052902 DOI: 10.1364/oe.27.010426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 03/13/2019] [Indexed: 06/09/2023]
Abstract
We present a heterogeneously coupled Si/SiO2/SiN waveguide structure that can achieve extremely high dispersions (> | ± 107| ps · nm-1km-1). A strong mode coupling between the Si and SiN waveguides introduces a normal dispersion to symmetric mode and an anomalous dispersion to anti-symmetric mode, and the large group velocity difference between the two waveguides results in such high dispersions. Geometric parameters of the structure control the peak dispersions and the central wavelength of the mode coupling, and these engineering capabilities are studied numerically. Analytical representations on the heterogeneously coupled waveguides are also introduced and these equations explain the effects of geometric parameters. This extremely dispersive waveguide scheme can be constructed with other material combinations as well and should be of interest in ultrafast signal processing and spectroscopic applications.
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21
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Yu M, Desiatov B, Okawachi Y, Gaeta AL, Lončar M. Coherent two-octave-spanning supercontinuum generation in lithium-niobate waveguides. OPTICS LETTERS 2019; 44:1222-1225. [PMID: 30821753 DOI: 10.1364/ol.44.001222] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 01/24/2019] [Indexed: 05/27/2023]
Abstract
We demonstrate coherent supercontinuum generation (SCG) in a monolithically integrated lithium-niobate waveguide, under the presence of second- and third-order nonlinear effects. We achieve more than two octaves of optical bandwidth in a 0.5-cm-long waveguide with 100-picojoule-level pulses. Dispersion engineering of the waveguide allows for spectral overlap between the SCG and the second harmonic, which enables direct detection of the carrier-envelope offset frequency fCEO using a single waveguide. We measure the fCEO of our femtosecond pump source with a 30-dB signal-to-noise ratio.
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van der Slot PJM, Porcel MAG, Boller KJ. Surface acoustic waves for acousto-optic modulation in buried silicon nitride waveguides. OPTICS EXPRESS 2019; 27:1433-1452. [PMID: 30696209 DOI: 10.1364/oe.27.001433] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 12/15/2018] [Indexed: 06/09/2023]
Abstract
We theoretically investigate the use of Rayleigh surface acoustic waves (SAWs) for refractive index modulation in optical waveguides consisting of amorphous dielectrics. Considering low-loss Si3N4 waveguides with a standard core cross-section of 4.4×0.03 μm2 size, buried 8-μm deep in a SiO2 cladding, we compare surface acoustic wave generation in various different geometries via a piezo-active, lead zirconate titanate film placed on top of the surface and driven via an interdigitized transducer (IDT). Using numerical solutions of the acoustic and optical wave equations, we determine the strain distribution of the SAW under resonant excitation. From the overlap of the acoustic strain field with the optical mode field, we calculate and maximize the attainable amplitude of index modulation in the waveguide. For the example of a near-infrared wavelength of 840 nm, a maximum shift in relative effective refractive index of 0.7x10-3 was obtained for TE polarized light, using an IDT period of 30-35 μm, a film thickness of 2.5-3.5 μm, and an IDT voltage of 10 V. For these parameters, the resonant frequency is in the range of 70-85 MHz. The maximum shift increases to 1.2x10-3, with a corresponding resonant frequency of 87 MHz, when the height of the cladding above the core is reduced to 3 μm. The relative index change is about 300 times higher than in previous work based on non-resonant proximity piezo-actuation, and the modulation frequency is about 200 times higher. Exploiting the maximum relative index change of 1.2×10-3 in a low-loss, balanced Mach-Zehnder modulator should allow full-contrast modulation in devices as short as 120 μm (half-wave voltage length product = 0.24 Vcm).
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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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Okawachi Y, Yu M, Cardenas J, Ji X, Klenner A, Lipson M, Gaeta AL. Carrier envelope offset detection via simultaneous supercontinuum and second-harmonic generation in a silicon nitride waveguide. OPTICS LETTERS 2018; 43:4627-4630. [PMID: 30272699 DOI: 10.1364/ol.43.004627] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 08/22/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate a chip-scale f-2f interferometer for carrier-envelope-offset frequency (fCEO) detection. This is enabled by simultaneously producing octave-spanning coherent supercontinuum generation and second-harmonic generation in a single dispersion-engineered silicon nitride waveguide. We measure the fCEO beatnote of an 80 MHz modelocked pump source with a signal-to-noise ratio of 25 dB. Our simple approach for f-2f interferometry enables a straightforward route towards a chip-scale self-referenced frequency comb source that can operate at low pulse energies.
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25
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Sethi P, Kallega R, Haldar A, Selvaraja SK. Compact broadband low-loss taper for coupling to a silicon nitride photonic wire. OPTICS LETTERS 2018; 43:3433-3436. [PMID: 30004523 DOI: 10.1364/ol.43.003433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 06/05/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate an ultra-compact waveguide taper on a silicon nitride platform. The proposed taper provides a coupling efficiency of 95% at a length of 19.5 μm in comparison to the standard linear taper of length 50 μm, which connects a 10 μm wide waveguide to a 1 μm wide photonic wire. The taper has a spectral response >75% spanning over 800 nm and resilience to fabrication variations; ±200 nm change in taper and end waveguide width varies transmission by <5%. We experimentally demonstrate taper insertion loss of <0.1 dB/transition for a taper as short as 19.5 μm, and reduce the footprint of the photonic device by 50.8% compared to the standard adiabatic taper. To the best of our knowledge, the proposed taper is the shortest waveguide taper ever reported in silicon nitride.
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26
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Octave Spanning Supercontinuum in Titanium Dioxide Waveguides. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8040543] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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27
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Singh N, Xin M, Vermeulen D, Shtyrkova K, Li N, Callahan PT, Magden ES, Ruocco A, Fahrenkopf N, Baiocco C, Kuo BPP, Radic S, Ippen E, Kärtner FX, Watts MR. Octave-spanning coherent supercontinuum generation in silicon on insulator from 1.06 μm to beyond 2.4 μm. LIGHT, SCIENCE & APPLICATIONS 2018; 7:17131. [PMID: 30839639 PMCID: PMC6107049 DOI: 10.1038/lsa.2017.131] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 08/31/2017] [Accepted: 09/01/2017] [Indexed: 05/19/2023]
Abstract
Efficient complementary metal-oxide semiconductor-based nonlinear optical devices in the near-infrared are in strong demand. Due to two-photon absorption in silicon, however, much nonlinear research is shifting towards unconventional photonics platforms. In this work, we demonstrate the generation of an octave-spanning coherent supercontinuum in a silicon waveguide covering the spectral region from the near- to shortwave-infrared. With input pulses of 18 pJ in energy, the generated signal spans the wavelength range from the edge of the silicon transmission window, approximately 1.06 to beyond 2.4 μm, with a -20 dB bandwidth covering 1.124-2.4 μm. An octave-spanning supercontinuum was also observed at the energy levels as low as 4 pJ (-35 dB bandwidth). We also measured the coherence over an octave, obtaining , in good agreement with the simulations. In addition, we demonstrate optimization of the third-order dispersion of the waveguide to strengthen the dispersive wave and discuss the advantage of having a soliton at the long wavelength edge of an octave-spanning signal for nonlinear applications. This research paves the way for applications, such as chip-scale precision spectroscopy, optical coherence tomography, optical frequency metrology, frequency synthesis and wide-band wavelength division multiplexing in the telecom window.
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Affiliation(s)
- Neetesh Singh
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Ming Xin
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Diedrik Vermeulen
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Katia Shtyrkova
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Nanxi Li
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- John A. Paulson School of Engineering and Applied Science, Harvard University, Cambridge, MA 02138, USA
| | - Patrick T Callahan
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Emir Salih Magden
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alfonso Ruocco
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Nicholas Fahrenkopf
- College of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, NY 12203, USA
| | - Christopher Baiocco
- College of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, NY 12203, USA
| | - Bill P-P Kuo
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92039, USA
| | - Stojan Radic
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92039, USA
| | - Erich Ippen
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Franz X Kärtner
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Centre for Free Electron Laser Science (CFEL)-DESY and University of Hamburg, Hamburg 22607, Germany
| | - Michael R Watts
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Okawachi Y, Yu M, Cardenas J, Ji X, Lipson M, Gaeta AL. Coherent, directional supercontinuum generation. OPTICS LETTERS 2017; 42:4466-4469. [PMID: 29088189 DOI: 10.1364/ol.42.004466] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 10/02/2017] [Indexed: 06/07/2023]
Abstract
We demonstrate a novel approach to producing coherent, directional supercontinuum and cascaded dispersive waves using dispersion engineering in waveguides. By pumping in the normal group-velocity dispersion (GVD) regime, with two zero-GVD points to one side of the pump, pulse compression of the first dispersive wave generated in the anomalous GVD region results in the generation of a second dispersive wave beyond the second zero-GVD point in the normal GVD regime. As a result, we achieve an octave-spanning supercontinuum generated primarily to one side of the pump spectrum. We theoretically investigate the dynamics and show that the generated spectrum is highly coherent. We experimentally confirm this dynamical behavior and the coherence properties in silicon nitride waveguides by performing direct detection of the carrier-envelope-offset frequency of our femtosecond pump source using an f-2f interferometer. Our technique offers a path towards a stabilized, high-power, integrated supercontinuum source with low noise and high coherence, with applications including direct comb spectroscopy.
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Krückel CJ, Fülöp A, Ye Z, Andrekson PA, Torres-Company V. Optical bandgap engineering in nonlinear silicon nitride waveguides. OPTICS EXPRESS 2017; 25:15370-15380. [PMID: 28788964 DOI: 10.1364/oe.25.015370] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 05/12/2017] [Indexed: 06/07/2023]
Abstract
Silicon nitride is a well-established material for photonic devices and integrated circuits. It displays a broad transparency window spanning from the visible to the mid-IR and waveguides can be manufactured with low losses. An absence of nonlinear multi-photon absorption in the erbium lightwave communications band has enabled various nonlinear optic applications in the past decade. Silicon nitride is a dielectric material whose optical and mechanical properties strongly depend on the deposition conditions. In particular, the optical bandgap can be modified with the gas flow ratio during low-pressure chemical vapor deposition (LPCVD). Here we show that this parameter can be controlled in a highly reproducible manner, providing an approach to synthesize the nonlinear Kerr coefficient of the material. This holistic empirical study provides relevant guidelines to optimize the properties of LPCVD silicon nitride waveguides for nonlinear optics applications that rely on the Kerr effect.
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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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Ishizawa A, Kou R, Goto T, Tsuchizawa T, Matsuda N, Hitachi K, Nishikawa T, Yamada K, Sogawa T, Gotoh H. Optical nonlinearity enhancement with graphene-decorated silicon waveguides. Sci Rep 2017; 7:45520. [PMID: 28401940 PMCID: PMC5388840 DOI: 10.1038/srep45520] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 02/27/2017] [Indexed: 11/28/2022] Open
Abstract
Broadband on-chip optical frequency combs (OFCs) are important for expanding the functionality of photonic integrated circuits. Here, we demonstrate a huge local optical nonlinearity enhancement using graphene. A waveguide is decorated with graphene by precisely manipulating graphene's area and position. Our approach simultaneously achieves both an extremely efficient supercontinuum and ultra-short pulse generation. With our graphene-decorated silicon waveguide (G-SWG), we have achieved enhanced spectral broadening of femtosecond pump pulses, along with an eightfold increase in the output optical intensity at a wavelength approximately 200 nm shorter than that of the pump pulses. We also found that this huge nonlinearity works as a compressor that effectively compresses pulse width from 80 to 15.7 fs. Our results clearly show the potential for our G-SWG to greatly boost the speed and capacity of future communications with lower power consumption, and our method will further decrease the required pump laser power because it can be applied to decorate various kinds of waveguides with various two-dimensional materials.
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Affiliation(s)
- Atsushi Ishizawa
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-0198, Japan
| | - Rai Kou
- NTT Nanophotonics Center, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-0198, Japan
- NTT Device Technology Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-0198, Japan
| | - Takahiro Goto
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-0198, Japan
- Tokyo Denki University, Department of Electrical and Electronic Engineering, 5 Senjyu Asahi-cho, Adachi-ku, Tokyo, 120-8551, Japan
| | - Tai Tsuchizawa
- NTT Nanophotonics Center, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-0198, Japan
- NTT Device Technology Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-0198, Japan
| | - Nobuyuki Matsuda
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-0198, Japan
- NTT Nanophotonics Center, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-0198, Japan
| | - Kenichi Hitachi
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-0198, Japan
| | - Tadashi Nishikawa
- Tokyo Denki University, Department of Electrical and Electronic Engineering, 5 Senjyu Asahi-cho, Adachi-ku, Tokyo, 120-8551, Japan
| | - Koji Yamada
- NTT Nanophotonics Center, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-0198, Japan
- NTT Device Technology Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-0198, Japan
| | - Tetsuomi Sogawa
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-0198, Japan
| | - Hideki Gotoh
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-0198, Japan
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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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Lin YY, Wu CL, Chi WC, Chiu YJ, Hung YJ, Chu AK, Lee CK. Self-phase modulation in highly confined submicron Ta 2O 5 channel waveguides. OPTICS EXPRESS 2016; 24:21633-21641. [PMID: 27661901 DOI: 10.1364/oe.24.021633] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Optical spectra broadening as a result self-phase modulation in a channel waveguide fabricated on a high quality tantalum pentoxide (Ta2O5) film by using RF sputtering is measured. The full-width at half maximum of the optical spectra for transverse electric (TE)/transverse magnetic (TM) polarizations of 42.5/31.7 nm is obtained using pulses of 10 nm at a wavelength of 800 nm with a peak-coupled power of 43.77 W. The nonlinear Kerr coefficients of 2.14 × 10-14 cm2/W and 1.92 × 10-14 cm2/W for TE and TM polarizations, respectively, are then extracted from the experiments using a theoretical model based on the method of moments. The obtained results on the nonlinearity further suggest that Ta2O5 is a promising material to develop nonlinear waveguide devices for integrated photonics.
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34
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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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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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36
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Choi JW, Chen GFR, Ng DKT, Ooi KJA, Tan DTH. Wideband nonlinear spectral broadening in ultra-short ultra - silicon rich nitride waveguides. Sci Rep 2016; 6:27120. [PMID: 27272558 PMCID: PMC4897639 DOI: 10.1038/srep27120] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 05/16/2016] [Indexed: 11/28/2022] Open
Abstract
CMOS-compatible nonlinear optics platforms with high Kerr nonlinearity facilitate the generation of broadband spectra based on self-phase modulation. Our ultra - silicon rich nitride (USRN) platform is designed to have a large nonlinear refractive index and low nonlinear losses at 1.55 μm for the facilitation of wideband spectral broadening. We investigate the ultrafast spectral characteristics of USRN waveguides with 1-mm-length, which have high nonlinear parameters (γ ∼ 550 W(-1)/m) and anomalous dispersion at 1.55 μm wavelength of input light. USRN add-drop ring resonators broaden output spectra by a factor of 2 compared with the bandwidth of input fs laser with the highest quality factors of 11000 and 15000. Two - fold self phase modulation induced spectral broadening is observed using waveguides only 430 μm in length, whereas a quadrupling of the output bandwidth is observed with USRN waveguides with a 1-mm-length. A broadening factor of around 3 per 1 mm length is achieved in the USRN waveguides, a value which is comparatively larger than many other CMOS-compatible platforms.
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Affiliation(s)
- Ju Won Choi
- Photonics Devices and System Group, Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Rd. 487372, Singapore
| | - George F. R. Chen
- Photonics Devices and System Group, Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Rd. 487372, Singapore
| | - D. K. T. Ng
- Data Storage Institute, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way #08-01 Innovis, 138634, Singapore
| | - Kelvin J. A. Ooi
- Photonics Devices and System Group, Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Rd. 487372, Singapore
| | - Dawn T. H. Tan
- Photonics Devices and System Group, Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Rd. 487372, Singapore
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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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38
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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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Wu ZX, Luo W, Tang SH, Xu F, Lu YQ. Influence of optical forces on nonlinear optical frequency conversion in nanoscale waveguide devices. OPTICS EXPRESS 2016; 24:1633-1640. [PMID: 26832541 DOI: 10.1364/oe.24.001633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We theoretically investigate the influence of optical gradient forces on nonlinear frequency conversion in a typical nanoscale optomechanical system, which consists of two parallel, suspended waveguides. The waveguides deform with the input power and the phase-matching wavelength changes along the waveguides. Utilizing the spread of deformations collectively allows phase matching over a wider range of pump wavelengths. The third harmonic phase-matching wavelength shift can be as large as 3.6 nm/mW when the waveguide length is 100 μm and the initial gap is 150 nm. It is analogous to chirping the poling period of quasi-phase-matched devices to extend their bandwidths, and allows broad third harmonic to be generated for uses such as biological spectroscopy. Finally, we discuss the conversion efficiency and the optimal phase-matching wavelength with a single-frequency pump.
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Ciret C, Leo F, Kuyken B, Roelkens G, Gorza SP. Observation of an optical event horizon in a silicon-on-insulator photonic wire waveguide. OPTICS EXPRESS 2016; 24:114-124. [PMID: 26832243 DOI: 10.1364/oe.24.000114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We report on the first experimental observation of an optical analogue of an event horizon in integrated nanophotonic waveguides, through the reflection of a continuous wave on an intense pulse. The experiment is performed in a dispersion-engineered silicon-on-insulator waveguide. In this medium, solitons do not suffer from Raman induced self-frequency shift as in silica fibers, a feature that is interesting for potential applications of optical event horizons. As shown by simulations, this also allows the observation of multiple reflections at the same time on fundamental solitons ejected by soliton fission.
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Ning T, Tan C, Niemi T, Kauranen M, Genty G. Enhancement of second-harmonic generation from silicon nitride with gold gratings. OPTICS EXPRESS 2015; 23:30695-30700. [PMID: 26698701 DOI: 10.1364/oe.23.030695] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We report strong enhancement of second-harmonic generation in a hybrid nanostructure with gold gratings embedded in a silicon nitride film. Compared to a flat silicon nitride film, the enhancement factor can be as large as 102 to 103 for transverse magnetic and electric polarizations, respectively in good agreement with numerical results calculated using finite element method. For both polarizations, the enhancement arises from a resonance between the waveguide modes and grating.
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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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Krückel CJ, Fülöp A, Klintberg T, Bengtsson J, Andrekson PA, Torres-Company V. Linear and nonlinear characterization of low-stress high-confinement silicon-rich nitride waveguides. OPTICS EXPRESS 2015; 23:25827-25837. [PMID: 26480096 DOI: 10.1364/oe.23.025827] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this paper we introduce a low-stress silicon enriched nitride platform that has potential for nonlinear and highly integrated optics. The manufacturing process of this platform is CMOS compatible and the increased silicon content allows tensile stress reduction and crack free layer growth of 700 nm. Additional benefits of the silicon enriched nitride is a measured nonlinear Kerr coefficient n(2) of 1.4·10(-18) m(2)/W (5 times higher than stoichiometric silicon nitride) and a refractive index of 2.1 at 1550 nm that enables high optical field confinement allowing high intensity nonlinear optics and light guidance even with small bending radii. We analyze the waveguide loss (∼1 dB/cm) in a spectrally resolved fashion and include scattering loss simulations based on waveguide surface roughness measurements. Detailed simulations show the possibility for fine dispersion and nonlinear engineering. In nonlinear experiments we present continuous-wave wavelength conversion and demonstrate that the material does not show nonlinear absorption effects. Finally, we demonstrate microfabrication of resonators with high Q-factors (∼10(5)).
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Wu CL, Chiu YJ, Chen CL, Lin YY, Chu AK, Lee CK. Four-wave-mixing in the loss low submicrometer Ta₂O₅ channel waveguide. OPTICS LETTERS 2015; 40:4528-4531. [PMID: 26421573 DOI: 10.1364/ol.40.004528] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A degenerate four-wave-mixing (FWM) operation in the Ta2O5 submicrometer channel waveguide has been successfully demonstrated. The propagation loss of 1.5 dB/cm and total insertion loss of 5.1 dB are realized in a 12.6 mm long waveguide with inverse taper structure. The wavelength and quadratic pumping power-dependent measurements on optical transmission confirm FWM performance and characterize the nonlinearity of waveguide. The conversion efficiency of -50 dB at coupled pump power of 40 mW is observed, suggesting that the nonlinear refractive index of Ta2O5 waveguide at 1550 nm is estimated to be 1×10(-14) cm2/W. Our primary results indicate that the Ta2O5 submicrometer channel waveguide has great potential in developing nonlinear waveguide applications.
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Ettabib MA, Xu L, Bogris A, Kapsalis A, Belal M, Lorent E, Labeye P, Nicoletti S, Hammani K, Syvridis D, Shepherd DP, Price JHV, Richardson DJ, Petropoulos P. Broadband telecom to mid-infrared supercontinuum generation in a dispersion-engineered silicon germanium waveguide. OPTICS LETTERS 2015; 40:4118-4121. [PMID: 26368726 DOI: 10.1364/ol.40.004118] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We demonstrate broadband supercontinuum generation (SCG) in a dispersion-engineered silicon-germanium waveguide. The 3 cm long waveguide is pumped by femtosecond pulses at 2.4 μm, and the generated supercontinuum extends from 1.45 to 2.79 μm (at the -30 dB point). The broadening is mainly driven by the generation of a dispersive wave in the 1.5-1.8 μm region and soliton fission. The SCG was modeled numerically, and excellent agreement with the experimental results was obtained.
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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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Singh N, Hudson DD, Eggleton BJ. Silicon-on-sapphire pillar waveguides for Mid-IR supercontinuum generation. OPTICS EXPRESS 2015; 23:17345-17354. [PMID: 26191744 DOI: 10.1364/oe.23.017345] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We propose pillar integrated silicon waveguides to exploit the entire transparent window of silicon. These geometries posses a broad and flat dispersion (from 2 to 6 μm) with four zero dispersion wavelengths. We calculate supercontinuum generation spanning over two octaves (2 to >8 μm) with long wavelengths interacting weakly with the lossy substrate. These structures have higher mode confinement in the silicon - away from the substrate, which makes them substrate independent and are promising for exploring new nonlinear phenomena and highly sensitive molecular sensing over the entire silicon's transparency range.
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Mayer AS, Klenner A, Johnson AR, Luke K, Lamont MRE, Okawachi Y, Lipson M, Gaeta AL, Keller U. Frequency comb offset detection using supercontinuum generation in silicon nitride waveguides. OPTICS EXPRESS 2015; 23:15440-15451. [PMID: 26193524 DOI: 10.1364/oe.23.015440] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present the first direct carrier-envelope-offset (CEO) frequency detection of a modelocked laser based on supercontinuum generation (SCG) in a CMOS-compatible silicon nitride (Si(3)N(4)) waveguide. With a coherent supercontinuum spanning more than 1.5 octaves from visible to beyond telecommunication wavelengths, we achieve self-referencing of SESAM modelocked diode-pumped Yb:CALGO lasers using standard f-to-2f interferometry. We directly obtain without amplification strong CEO beat signals for both a 100-MHz and 1-GHz pulse repetition rate laser. High signal-to-noise ratios (SNR) of > 25 dB and even > 30 dB have been generated with only 30 pJ and 36 pJ of coupled pulse energy from the megahertz and gigahertz laser respectively. We compare these results to self-referencing using a commercial photonic crystal fiber and find that the required peak power for CEO beat detection with a comparable SNR is lowered by more than an order of magnitude when using a Si(3)N(4) waveguide.
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Zhao H, Kuyken B, Clemmen S, Leo F, Subramanian A, Dhakal A, Helin P, Severi S, Brainis E, Roelkens G, Baets R. Visible-to-near-infrared octave spanning supercontinuum generation in a silicon nitride waveguide. OPTICS LETTERS 2015; 40:2177-2180. [PMID: 26393693 DOI: 10.1364/ol.40.002177] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The generation of an octave spanning supercontinuum covering 488-978 nm (at -30 dB) is demonstrated for the first time on-chip. This result is achieved by dispersion engineering a 1-cm-long Si3N4 waveguide and pumping it with an 100-fs Ti:Sapphire laser emitting at 795 nm. This work offers a bright broadband source for biophotonic applications and frequency metrology.
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Dave UD, Kuyken B, Leo F, Gorza SP, Combrie S, De Rossi A, Raineri F, Roelkens G. Nonlinear properties of dispersion engineered InGaP photonic wire waveguides in the telecommunication wavelength range. OPTICS EXPRESS 2015; 23:4650-4657. [PMID: 25836502 DOI: 10.1364/oe.23.004650] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We propose high index contrast InGaP photonic wires as a platform for the integration of nonlinear optical functions in the telecom wavelength window. We characterize the linear and nonlinear properties of these waveguide structures. Waveguides with a linear loss of 12 dB/cm and which are coupled to a single mode fiber through gratings with a -7.5 dB coupling loss are realized. From four wave mixing experiments, we extract the real part of the nonlinear parameter γ to be 475 ± 50 W(-1)m(-1) and from nonlinear transmission measurements we infer the absence of two-photon absorption and measure a three-photon absorption coefficient of (2.5 ± 0.5) x 10(-2) cm(3)GW(-2).
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