101
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Fülöp A, Mazur M, Lorences-Riesgo A, Eriksson TA, Wang PH, Xuan Y, Leaird DE, Qi M, Andrekson PA, Weiner AM, Torres-Company V. Long-haul coherent communications using microresonator-based frequency combs. OPTICS EXPRESS 2017; 25:26678-26688. [PMID: 29092153 DOI: 10.1364/oe.25.026678] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 10/15/2017] [Indexed: 06/07/2023]
Abstract
Microresonator-based frequency combs are strong contenders as light sources for wavelength-division multiplexing (WDM). Recent experiments have shown the potential of microresonator combs for replacing a multitude of WDM lasers with a single laser-pumped device. Previous demonstrations have however focused on short-distance few-span links reaching an impressive throughput at the expense of transmission distance. Here we report the first long-haul coherent communication demonstration using a microresonator-based comb source. We modulated polarization multiplexed (PM) quadrature phase-shift keying-data onto the comb lines allowing transmission over more than 6300 km in a single-mode fiber. In a second experiment, we reached beyond 700 km with the PM 16 quadrature amplitude modulation format. To the best of our knowledge, these results represent the longest fiber transmission ever achieved using an integrated comb source.
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102
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Moscoso-Mártir A, Müller J, Hauck J, Chimot N, Setter R, Badihi A, Rasmussen DE, Garreau A, Nielsen M, Islamova E, Romero-García S, Shen B, Sandomirsky A, Rockman S, Li C, Sharif Azadeh S, Lo GQ, Mentovich E, Merget F, Lelarge F, Witzens J. Silicon Photonics Transmitter with SOA and Semiconductor Mode-Locked Laser. Sci Rep 2017; 7:13857. [PMID: 29066785 PMCID: PMC5654767 DOI: 10.1038/s41598-017-14347-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 10/10/2017] [Indexed: 11/10/2022] Open
Abstract
We experimentally investigate an optical link relying on silicon photonics transmitter and receiver components as well as a single section semiconductor mode-locked laser as a light source and a semiconductor optical amplifier for signal amplification. A transmitter based on a silicon photonics resonant ring modulator, an external single section mode-locked laser and an external semiconductor optical amplifier operated together with a standard receiver reliably supports 14 Gbps on-off keying signaling with a signal quality factor better than 7 for 8 consecutive comb lines, as well as 25 Gbps signaling with a signal quality factor better than 7 for one isolated comb line, both without forward error correction. Resonant ring modulators and Germanium waveguide photodetectors are further hybridly integrated with chip scale driver and receiver electronics, and their co-operability tested. These experiments will serve as the basis for assessing the feasibility of a silicon photonics wavelength division multiplexed link relying on a single section mode-locked laser as a multi-carrier light source.
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Affiliation(s)
- Alvaro Moscoso-Mártir
- Institute of Integrated Photonics (IPH) of RWTH Aachen University, Sommerfeldstr. 24, D-52074, Aachen, Germany
| | - Juliana Müller
- Institute of Integrated Photonics (IPH) of RWTH Aachen University, Sommerfeldstr. 24, D-52074, Aachen, Germany
| | - Johannes Hauck
- Institute of Integrated Photonics (IPH) of RWTH Aachen University, Sommerfeldstr. 24, D-52074, Aachen, Germany
| | - Nicolas Chimot
- III-V Lab, Campus de Polytechnique, 1 av. Augustin Fresnel, F-91767, Palaiseau Cedex, France.,3SP Technologies S.A.S., Route de Villejust, Nozay Cedex, F-91625, France
| | - Rony Setter
- Mellanox Technologies, Hakidma 26, Ofer Industrial Park, Yokneam, Israel
| | - Avner Badihi
- Mellanox Technologies, Hakidma 26, Ofer Industrial Park, Yokneam, Israel
| | - Daniel E Rasmussen
- Mellanox Technologies, Hakidma 26, Ofer Industrial Park, Yokneam, Israel
| | - Alexandre Garreau
- III-V Lab, Campus de Polytechnique, 1 av. Augustin Fresnel, F-91767, Palaiseau Cedex, France
| | - Mads Nielsen
- Mellanox Technologies, Hakidma 26, Ofer Industrial Park, Yokneam, Israel
| | - Elmira Islamova
- Institute of Integrated Photonics (IPH) of RWTH Aachen University, Sommerfeldstr. 24, D-52074, Aachen, Germany.,Innolume GmbH, Konrad-Adenauer-Allee 11, Dortmund, D-44263, Germany
| | - Sebastián Romero-García
- Institute of Integrated Photonics (IPH) of RWTH Aachen University, Sommerfeldstr. 24, D-52074, Aachen, Germany
| | - Bin Shen
- Institute of Integrated Photonics (IPH) of RWTH Aachen University, Sommerfeldstr. 24, D-52074, Aachen, Germany
| | - Anna Sandomirsky
- Mellanox Technologies, Hakidma 26, Ofer Industrial Park, Yokneam, Israel
| | - Sylvie Rockman
- Mellanox Technologies, Hakidma 26, Ofer Industrial Park, Yokneam, Israel
| | - Chao Li
- Singapore Institute of Microelectronics (IME)/A*STAR, Science Park Road 11, Singapore Science Park II, Singapore, 117685, Singapore
| | - Saeed Sharif Azadeh
- Institute of Integrated Photonics (IPH) of RWTH Aachen University, Sommerfeldstr. 24, D-52074, Aachen, Germany
| | - Guo-Qiang Lo
- Singapore Institute of Microelectronics (IME)/A*STAR, Science Park Road 11, Singapore Science Park II, Singapore, 117685, Singapore
| | - Elad Mentovich
- Mellanox Technologies, Hakidma 26, Ofer Industrial Park, Yokneam, Israel
| | - Florian Merget
- Institute of Integrated Photonics (IPH) of RWTH Aachen University, Sommerfeldstr. 24, D-52074, Aachen, Germany
| | - François Lelarge
- III-V Lab, Campus de Polytechnique, 1 av. Augustin Fresnel, F-91767, Palaiseau Cedex, France.,Almae Technologies, Site Data 4, Route de Nozay, Marcoussis, F-91460, France
| | - Jeremy Witzens
- Institute of Integrated Photonics (IPH) of RWTH Aachen University, Sommerfeldstr. 24, D-52074, Aachen, Germany.
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103
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Sahni MO, Trebaol S, Bramerie L, Joindot M, Ó Dúill SP, Murdoch SG, Barry LP, Besnard P. Frequency noise reduction performance of a feed-forward heterodyne technique: application to an actively mode-locked laser diode. OPTICS LETTERS 2017; 42:4000-4003. [PMID: 28957182 DOI: 10.1364/ol.42.004000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 09/02/2017] [Indexed: 06/07/2023]
Abstract
We report on the frequency noise reduction performance of a feed-forward technique. The Letter is based on frequency noise measurements that allow the spectral response of the feed-forward phase noise correction to be determined. The main limitation to the noise compensation is attributed to the local oscillator flicker noise and the noise added by the optoelectronic loop elements. The technique is applied to an actively mode-locked laser diode demonstrating, at the output of the system, an optical frequency comb source with 14 comb lines reduced to sub-kilohertz intrinsic linewidth.
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104
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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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105
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Abstract
Optical cavities transmit light only at discrete resonant frequencies, which are well-separated in micro-structures. Despite attempts at the construction of planar ‘white-light cavities’, the benefits accrued upon optically interacting with a cavity – such as resonant field buildup – have remained confined to narrow linewidths. Here, we demonstrate achromatic optical transmission through a planar Fabry-Pérot micro-cavity via angularly multiplexed phase-matching that exploits a bio-inspired grating configuration. By correlating each wavelength with an appropriate angle of incidence, a continuous spectrum resonates and the micro-cavity is rendered transparent. The locus of a single-order 0.7-nm-wide resonance is de-slanted in spectral-angular space to become a 60-nm-wide achromatic resonance spanning multiple cavity free-spectral-ranges. The result is an ‘omni-resonant’ planar micro-cavity in which light resonates continuously over a broad spectral span. This approach severs the link between the resonance bandwidth and the cavity-photon lifetime, thereby promising resonant enhancement of linear and nonlinear optical effects over broad bandwidths in ultrathin devices.
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106
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Liao P, Bao C, Kordts A, Karpov M, Pfeiffer MHP, Zhang L, Cao Y, Almaiman A, Mohajerin-Ariaei A, Tur M, Fejer MM, Kippenberg TJ, Willner AE. Pump-linewidth-tolerant wavelength multicasting using soliton Kerr frequency combs. OPTICS LETTERS 2017; 42:3177-3180. [PMID: 28809901 DOI: 10.1364/ol.42.003177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 07/12/2017] [Indexed: 06/07/2023]
Abstract
We experimentally demonstrate pump-linewidth-tolerant wavelength multicasting using microresonator-based soliton Kerr frequency combs. When Kerr comb lines serve as coherent pumps in a periodically poled lithium niobate waveguide, the linewidth of the multicast signal almost remains that of the original signal at different linewidths of Kerr combs, ranging from 100 kHz to 1 MHz. However, in conventional multicasting where free-running (FR) pumps are used, the linewidth of the converted signal significantly increases. Furthermore, the error vector magnitude (EVM) performance demonstrates eight-fold error-free multicasting of 10 Gbaud 16-quadrature amplitude modulation signals, even when the linewidths of the Kerr combs are as broad as 1 MHz (no Kalman filtering algorithm in the receiver). In contrast, the EVM performance of the signal copy is degraded with an FR laser as a dummy pump.
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107
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Pelusi M, Choudhary A, Inoue T, Marpaung D, Eggleton BJ, Solis-Trapala K, Tan HN, Namiki S. Low noise frequency comb carriers for 64-QAM via a Brillouin comb amplifier. OPTICS EXPRESS 2017; 25:17847-17863. [PMID: 28789276 DOI: 10.1364/oe.25.017847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 07/14/2017] [Indexed: 06/07/2023]
Abstract
Optical frequency comb lines with poor carrier to noise ratio (CNR) are significantly improved by Brillouin amplification using its extreme narrow bandwidth gain to suppress out of band noise, enabling higher quality signal modulation. Its application to spectral lines of narrow 10 GHz pitch and poor CNR is shown to suppress the otherwise strong phase distortion caused by poor CNR after encoding with 96 Gb/s DP-64-QAM signals and restore the bit error rate (BER) to below the limit for standard forward error correction (FEC). This is also achieved with the required frequency shifted optical pump for amplification obtained by seeding it from the comb itself, sparing the need for lasers and frequency locking. Simultaneous CNR improvement for 38 comb lines is also achieved with BER restored to below the FEC limit, enabled by a multi-line pump that is pre-dispersed to suppress its spectral distortion from the Kerr effect in the gain medium. Carrier performance at minimum BER shows minimal noise impact from the Brillouin amplifier itself. The results highlight the unique advantage of Brillouin gain for phase sensitive communications in transforming otherwise noisy spectral lines into useful high quality signal carriers.
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108
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Okawachi Y, Yu M, Venkataraman V, Latawiec PM, Griffith AG, Lipson M, Lončar M, Gaeta AL. Competition between Raman and Kerr effects in microresonator comb generation. OPTICS LETTERS 2017; 42:2786-2789. [PMID: 28708169 DOI: 10.1364/ol.42.002786] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 06/19/2017] [Indexed: 05/27/2023]
Abstract
We investigate the effects of Raman and Kerr gain in crystalline microresonators and determine the conditions required to generate mode-locked frequency combs. We show theoretically that a strong, narrowband Raman gain determines a maximum microresonator size allowable to achieve comb formation. We verify this condition experimentally in diamond and silicon microresonators and show that there exists a competition between Raman and Kerr effects that leads to the existence of two different comb states.
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109
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Emmer H, Chen CT, Saive R, Friedrich D, Horie Y, Arbabi A, Faraon A, Atwater HA. Fabrication of Single Crystal Gallium Phosphide Thin Films on Glass. Sci Rep 2017; 7:4643. [PMID: 28680143 PMCID: PMC5498489 DOI: 10.1038/s41598-017-05012-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 05/30/2017] [Indexed: 11/09/2022] Open
Abstract
Due to its high refractive index and low absorption coefficient, gallium phosphide is an ideal material for photonic structures targeted at the visible wavelengths. However, these properties are only realized with high quality epitaxial growth, which limits substrate choice and thus possible photonic applications. In this work, we report the fabrication of single crystal gallium phosphide thin films on transparent glass substrates via transfer bonding. GaP thin films on Si (001) and (112) grown by MOCVD are bonded to glass, and then the growth substrate is removed with a XeF2 vapor etch. The resulting GaP films have surface roughnesses below 1 nm RMS and exhibit room temperature band edge photoluminescence. Magnesium doping yielded p-type films with a carrier density of 1.6 × 1017 cm-3 that exhibited mobilities as high as 16 cm2V-1s-1. Due to their unique optical properties, these films hold much promise for use in advanced optical devices.
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Affiliation(s)
- Hal Emmer
- Applied Physics and Materials Science, California Institute of Technology, Pasadena, 91125, USA
| | - Christopher T Chen
- Applied Physics and Materials Science, California Institute of Technology, Pasadena, 91125, USA
| | - Rebecca Saive
- Applied Physics and Materials Science, California Institute of Technology, Pasadena, 91125, USA
| | - Dennis Friedrich
- Joint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, CA, 91125, USA.,Institute for Solar Fuels, Helmholtz-Zentrum Berlin, für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109, Berlin, Germany
| | - Yu Horie
- Applied Physics and Materials Science, California Institute of Technology, Pasadena, 91125, USA
| | - Amir Arbabi
- Applied Physics and Materials Science, California Institute of Technology, Pasadena, 91125, USA
| | - Andrei Faraon
- Applied Physics and Materials Science, California Institute of Technology, Pasadena, 91125, USA
| | - Harry A Atwater
- Applied Physics and Materials Science, California Institute of Technology, Pasadena, 91125, USA.
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110
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Bao C, Xuan Y, Jaramillo-Villegas JA, Leaird DE, Qi M, Weiner AM. Direct soliton generation in microresonators. OPTICS LETTERS 2017; 42:2519-2522. [PMID: 28957274 DOI: 10.1364/ol.42.002519] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 05/26/2017] [Indexed: 06/07/2023]
Abstract
We investigate, numerically and experimentally, the effect of thermo-optical (TO) chaos on soliton generation dynamics in microresonators. Numerical simulations that include the thermal dynamics show that the generated solitons can either survive or annihilate when the pump laser is scanned from blue to red and then stop at a fixed wavelength; the outcome is stochastic and is strongly related to the number of solitons generated. The random fluctuations of the cavity resonance occurring under TO chaos are also found to trigger delayed spontaneous soliton generation after the laser scan ends, which could enable soliton excitation with slow laser tuning speed. Stochastic soliton annihilation/survival, as well as delayed spontaneous soliton generation, is observed experimentally in a silicon-nitride microresonator.
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111
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Marin-Palomo P, Kemal JN, Karpov M, Kordts A, Pfeifle J, Pfeiffer MHP, Trocha P, Wolf S, Brasch V, Anderson MH, Rosenberger R, Vijayan K, Freude W, Kippenberg TJ, Koos C. Microresonator-based solitons for massively parallel coherent optical communications. Nature 2017; 546:274-279. [DOI: 10.1038/nature22387] [Citation(s) in RCA: 554] [Impact Index Per Article: 79.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 04/18/2017] [Indexed: 11/09/2022]
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112
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Lei X, Gu Z, Ma J, Qin G, Chen Z, Chen S. Investigation of the local dispersion change in anomalous dispersion microcavity and quantitative analysis of the phase-matching in Kerr comb generation. APPLIED OPTICS 2017; 56:4828-4834. [PMID: 29047621 DOI: 10.1364/ao.56.004828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 05/06/2017] [Indexed: 06/07/2023]
Abstract
We numerically simulate Kerr comb generation in an anomalous dispersion microcavity by modal expansion method and demonstrate that the initiation of comb generation is affected by the change of local dispersion possibly caused by avoided mode crossings. We also quantitatively analyze the instantaneous phase matching of different modes and reveal the characteristics of energy distribution in different modes in the dynamics of comb generation. We demonstrate that the local dispersion change can control the Kerr comb to transform between Type I and Type II combs. We also find that local dispersion is closely related to the stability of the power of Kerr comb lines, something that can change the dynamical state of the system near the Hamiltonian-Hopf bifurcation under an anomalous dispersion regime from a quasi-periodic oscillation state to a periodic state (Turing patterns).
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113
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Huang SW, Vinod AK, Yang J, Yu M, Kwong DL, Wong CW. Quasi-phase-matched multispectral Kerr frequency comb. OPTICS LETTERS 2017; 42:2110-2113. [PMID: 28569858 DOI: 10.1364/ol.42.002110] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 04/25/2017] [Indexed: 06/07/2023]
Abstract
We study a new type of Kerr frequency comb where the momentum conservation law is fulfilled by azimuthal modulation of the waveguide dispersion. The concept can expand the parametric range in which a Kerr frequency comb is obtained. In a good agreement with the theoretical analysis, we demonstrate a multispectral Kerr frequency comb covering important fiber-optic communication bands. Comb coherence and absence of a sub-comb offset are confirmed by continuous-wave heterodyne beat note and amplitude noise spectra measurements. The device can be used for achieving broadband optical frequency synthesizers and high-capacity coherent communication.
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114
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Kartashov YV, Alexander O, Skryabin DV. Multistability and coexisting soliton combs in ring resonators: the Lugiato-Lefever approach. OPTICS EXPRESS 2017; 25:11550-11555. [PMID: 28788718 DOI: 10.1364/oe.25.011550] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We are reporting that the Lugiato-Lefever equation describing the frequency comb generation in ring resonators with the localized pump and loss terms also describes the simultaneous nonlinear resonances leading to the multistability of nonlinear modes and coexisting solitons that are associated with the spectrally distinct frequency combs.
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115
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Oreshnikov I, Skryabin DV. Multiple nonlinear resonances and frequency combs in bottle microresonators. OPTICS EXPRESS 2017; 25:10306-10311. [PMID: 28468403 DOI: 10.1364/oe.25.010306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We introduce the generalized Lugiato-Lefever equation describing nonlinear effects in the bottle microresonators. We demonstrate that the nonlinear modes of these resonators can form multiple coexisting and overlapping nonlinear resonances and that their instabilities lead to the generation of the low repetition rate frequency combs.
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116
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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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117
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Liao P, Bao C, Kordts A, Karpov M, Pfeiffer MHP, Zhang L, Mohajerin-Ariaei A, Cao Y, Almaiman A, Ziyadi M, Wilkinson SR, Tur M, Kippenberg TJ, Willner AE. Dependence of a microresonator Kerr frequency comb on the pump linewidth. OPTICS LETTERS 2017; 42:779-782. [PMID: 28198861 DOI: 10.1364/ol.42.000779] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We experimentally investigate the dependence of Kerr comb generation, comb linewidth, and coherent system performance on the pump linewidth in a microresonator. We find that the generation of the primary comb can have a larger tolerance to the pump linewidth compared with that of the low-phase-noise comb. In addition, the linewidths of the generated combs are almost linearly dependent on the pump linewidth in the primary and low-phase-noise states. Furthermore, the optical signal-to-noise ratio penalty between the pump and generated Kerr combs in a coherent communication system is less than 0.2 dB in both the primary and low-phase-noise states, showing that Kerr frequency combs in these two states can have similar coherent system performance to the pump.
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118
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Bao C, Liao P, Kordts A, Zhang L, Karpov M, Pfeiffer MHP, Cao Y, Yan Y, Almaiman A, Xie G, Mohajerin-Ariaei A, Li L, Ziyadi M, Wilkinson SR, Tur M, Kippenberg TJ, Willner AE. Dual-pump generation of high-coherence primary Kerr combs with multiple sub-lines. OPTICS LETTERS 2017; 42:595-598. [PMID: 28146536 DOI: 10.1364/ol.42.000595] [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
We experimentally generate high-coherence primary Kerr combs with multiple sub-lines by using dual pumps and demonstrate the application of a primary comb state in multichannel communications. We find that more than 10 primary comb lines can be generated within the spectrum of modulation instability gain in our microring resonator. The generation is also verified by numerical simulations and the measured linewidth confirms the high coherence of the generated primary comb lines. We also demonstrate the high-coherence characteristics in a coherent communication experiment, in which each comb line is encoded with 20 Gbaud quadrature phase-shift-keyed signals.
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119
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Kato T, Hori A, Suzuki R, Fujii S, Kobatake T, Tanabe T. Transverse mode interaction via stimulated Raman scattering comb in a silica microcavity. OPTICS EXPRESS 2017; 25:857-866. [PMID: 28157973 DOI: 10.1364/oe.25.000857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Comb generation in different mode families via a stimulated Raman scattering (SRS) process is studied using a silica toroid microcavity. The broad gain bandwidth of SRS in silica allows us to excite longitudinal modes at long wavelengths belonging to mode families that are either the same as or different from the pump mode. We found through experiment and numerical analysis, that an SRS comb in a different mode family with a high quality factor (Q) is excited when we pump in a low-Q mode. No transverse mode interaction occurs when we excite in a high-Q mode resulting the generation of a single comb family. We studied the condition of the transverse mode interaction while varying the mode overlap and Q of the Raman mode. Our experimental results are in good agreement with the analysis and this enables us to control the generation of one- and two-mode combs.
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Brasch V, Lucas E, Jost JD, Geiselmann M, Kippenberg TJ. Self-referenced photonic chip soliton Kerr frequency comb. LIGHT, SCIENCE & APPLICATIONS 2017; 6:e16202. [PMID: 30167198 PMCID: PMC6061893 DOI: 10.1038/lsa.2016.202] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 08/13/2016] [Accepted: 08/17/2016] [Indexed: 05/04/2023]
Abstract
Self-referencing turns pulsed laser systems into self-referenced frequency combs. Such frequency combs allow counting of optical frequencies and have a wide range of applications. The required optical bandwidth to implement self-referencing is typically obtained via nonlinear broadening in optical fibers. Recent advances in the field of Kerr frequency combs have provided a path toward the development of compact frequency comb sources that provide broadband frequency combs, exhibit microwave repetition rates and are compatible with on-chip photonic integration. These devices have the potential to significantly expand the use of frequency combs. Yet to date, self-referencing of such Kerr frequency combs has only been attained by applying conventional, fiber-based broadening techniques. Here we demonstrate external broadening-free self-referencing of a Kerr frequency comb. An optical spectrum spanning two-thirds of an octave is directly synthesized from a continuous wave laser-driven silicon nitride microresonator using temporal dissipative Kerr soliton formation and soliton Cherenkov radiation. Using this coherent bandwidth and two continuous wave transfer lasers in a 2f-3f self-referencing scheme, we are able to detect the offset frequency of the soliton Kerr frequency comb. By stabilizing the repetition rate to a radio frequency reference, the self-referenced frequency comb is used to count and track the continuous wave pump laser's frequency. This work demonstrates the principal ability of soliton Kerr frequency combs to provide microwave-to-optical clockworks on a chip.
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Affiliation(s)
- Victor Brasch
- />École Polytechnique Fédérale de Lausanne (EPFL) – IPHYS, Lausanne CH-1015, Switzerland
| | - Erwan Lucas
- />École Polytechnique Fédérale de Lausanne (EPFL) – IPHYS, Lausanne CH-1015, Switzerland
| | - John D Jost
- />École Polytechnique Fédérale de Lausanne (EPFL) – IPHYS, Lausanne CH-1015, Switzerland
| | - Michael Geiselmann
- />École Polytechnique Fédérale de Lausanne (EPFL) – IPHYS, Lausanne CH-1015, Switzerland
| | - Tobias J Kippenberg
- />École Polytechnique Fédérale de Lausanne (EPFL) – IPHYS, Lausanne CH-1015, Switzerland
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121
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Lorences-Riesgo A, Mazur M, Eriksson TA, Andrekson PA, Karlsson M. Self-homodyne 24×32-QAM superchannel receiver enabled by all-optical comb regeneration using brillouin amplification. OPTICS EXPRESS 2016; 24:29714-29723. [PMID: 28059355 DOI: 10.1364/oe.24.029714] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We demonstrate and characterize an all-optical self-homodyne (SH) frequency superchannel enabled by comb regeneration at the receiver. In order to generate the superchannel, we use a frequency comb with 26 carriers spaced by 25 GHz at the transmitter, from which 24 carriers are modulated with polarization-multiplexed 32 quadrature amplitude modulation (PM 32-QAM) data. To enable comb regeneration at the receiver side, the two central carriers remain unmodulated. High fidelity comb regeneration is achieved by filtering the two unmodulated carriers with an approximately 25 MHz wide optical filter based on Brillouin amplification before a parametric mixer. The carriers from the regenerated comb are then used as local oscillator for SH detection. We demonstrate that all 24 carriers can be detected with an optical signal-to-noise ratio (OSNR) penalty lower than 2.5 dB in a back-to-back scenario. We also demonstrate that the whole superchannel can be transmitted through 120 km of single-mode fiber (SMF) and be detected with bit-error rate (BER) below 0.015.
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122
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Brasch V, Geiselmann M, Pfeiffer MHP, Kippenberg TJ. Bringing short-lived dissipative Kerr soliton states in microresonators into a steady state. OPTICS EXPRESS 2016; 24:29312-29320. [PMID: 27958591 DOI: 10.1364/oe.24.029312] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Dissipative Kerr solitons have recently been generated in optical microresonators, enabling ultrashort optical pulses at microwave repetition rates, that constitute coherent and numerically predictable Kerr frequency combs. However, the seeding and excitation of the temporal solitons is associated with changes in the intracavity power that can lead to large thermal resonance shifts and render the soliton states in most commonly used resonator platforms short lived. Here we describe a "power kicking" method to overcome this instability by modulating the power of the pump laser. With this method also initially very short-lived (of the order of 100 ns) soliton states can be brought into a steady state in contrast to techniques reported earlier which relied on an adjustment of the laser scan speed only. Once the soliton state is in a steady state it can persist for hours and is thermally self-locked.
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123
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Saleh K, Chembo YK. On the phase noise performance of microwave and millimeter-wave signals generated with versatile Kerr optical frequency combs. OPTICS EXPRESS 2016; 24:25043-25056. [PMID: 27828444 DOI: 10.1364/oe.24.025043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We investigate the phase noise performance of micro- and millimeter-wave signals generated using a ultra-high Q whispering gallery mode disk-resonator with Kerr nonlinearity. Our study focuses on the stability of the optical spectra and on the performances of the corresponding microwave and millimeter-wave beat notes in terms of power and phase noise. The blue slope of an optical mode of the resonator, allowing for the generation of optical frequency combs, is accurately explored in order to identify various comb patterns. Each of these patterns is characterized in the optical and radio-frequency domains. Phase noise levels below -100 dBc/Hz at 10 kHz offset have been achieved for beat notes in the radio-frequency spectrum at 12 GHz, 18 GHz, 24 GHz, 30 GHz, and 36 GHz with the same resonator.
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124
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Kemal JN, Pfeifle J, Marin-Palomo P, Pascual MDG, Wolf S, Smyth F, Freude W, Koos C. Multi-wavelength coherent transmission using an optical frequency comb as a local oscillator. OPTICS EXPRESS 2016; 24:25432-25445. [PMID: 27828482 DOI: 10.1364/oe.24.025432] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Steadily increasing data rates of optical interfaces require spectrally efficient coherent transmission using higher-order modulation formats in combination with scalable wavelength-division multiplexing (WDM) schemes. At the transmitter, optical frequency combs (OFC) lend themselves to particularly precise multi-wavelength sources for WDM transmission. In this work we demonstrate that these advantages can also be leveraged at the receiver by using an OFC as a highly scalable multi-wavelength local oscillator (LO) for coherent detection. In our experiments, we use a pair of OFC that rely on gain switching of injection-locked semiconductor lasers both for WDM transmission and intradyne reception. We synchronize the center frequency and the free spectral range of the receiver comb to the transmitter, keeping the intradyne frequencies for all data channels below 15 MHz. Using 13 WDM channels, we transmit an aggregate line rate (net data rate) of 1.104 Tbit/s (1.032 Tbit/s) over a 10 km long standard single mode fiber at a spectral efficiency of 5.16 bit/s/Hz. To the best of our knowledge, this is the first demonstration of coherent WDM transmission using synchronized frequency combs as light source at the transmitter and as multi-wavelength LO at the receiver.
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125
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Webb KE, Erkintalo M, Coen S, Murdoch SG. Experimental observation of coherent cavity soliton frequency combs in silica microspheres. OPTICS LETTERS 2016; 41:4613-4616. [PMID: 28005849 DOI: 10.1364/ol.41.004613] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report on the experimental observation of coherent cavity soliton frequency combs in silica microspheres. Specifically, we demonstrate that careful alignment of the microsphere relative to the coupling fiber taper allows for the suppression of higher-order spatial modes, reducing mode interactions and enabling soliton formation. Our measurements show that the temporal cavity solitons have sub-100-fs durations, exhibit considerable Raman self-frequency shift, and generally come in groups of three or four, occasionally with equidistant spacing in the time domain. RF amplitude noise measurements and spectral interferometry confirm the high coherence of the observed soliton frequency combs, and numerical simulations show good agreement with experiments.
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126
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Qian H, Xiao Y, Liu Z. Giant Kerr response of ultrathin gold films from quantum size effect. Nat Commun 2016; 7:13153. [PMID: 27721498 PMCID: PMC5062544 DOI: 10.1038/ncomms13153] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 09/08/2016] [Indexed: 11/09/2022] Open
Abstract
With the size of plasmonic devices entering into the nanoscale region, the impact of quantum physics needs to be considered. In the past, the quantum size effect on linear material properties has been studied extensively. However, the nonlinear aspects have not been explored much so far. On the other hand, much effort has been put into the field of integrated nonlinear optics and a medium with large nonlinearity is desirable. Here we study the optical nonlinear properties of a nanometre scale gold quantum well by using the z-scan method and nonlinear spectrum broadening technique. The quantum size effect results in a giant optical Kerr susceptibility, which is four orders of magnitude higher than the intrinsic value of bulk gold and several orders larger than traditional nonlinear media. Such high nonlinearity enables efficient nonlinear interaction within a microscopic footprint, making quantum metallic films a promising candidate for integrated nonlinear optical applications.
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Affiliation(s)
- Haoliang Qian
- Department of Electrical and Computer Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
| | - Yuzhe Xiao
- Department of Electrical and Computer Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
| | - Zhaowei Liu
- Department of Electrical and Computer Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA.,Materials Science and Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA.,Center for Memory and Recording Research, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
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127
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Abstract
Optical frequency comb sources provide thousands of precise and accurate optical lines in a single device enabling the broadband and high-speed detection required in many applications. A main challenge is to parallelize the detection over the widest possible band while bringing the resolution to the single comb-line level. Here we propose a solution based on the combination of a frequency comb source and a fibre spectrometer, exploiting all-fibre technology. Our system allows for simultaneous measurement of 500 isolated comb lines over a span of 0.12 THz in a single acquisition; arbitrarily larger span are demonstrated (3,500 comb lines over 0.85 THz) by doing sequential acquisitions. The potential for precision measurements is proved by spectroscopy of acetylene at 1.53 μm. Being based on all-fibre technology, our system is inherently low-cost, lightweight and may lead to the development of a new class of broadband high-resolution spectrometers. An ideal optical frequency-comb system should combine both single-line spectral resolution and a bandwidth broad enough to cover as many lines as possible. Here, the authors incorporate a fibre spectrometer to detect approximately 500 comb-lines with an instrument resolution of 120 megahertz.
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128
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Bao C, Liao P, Kordts A, Karpov M, Pfeiffer MHP, Zhang L, Yan Y, Xie G, Cao Y, Almaiman A, Ziyadi M, Li L, Zhao Z, Mohajerin-Ariaei A, Wilkinson SR, Tur M, Fejer MM, Kippenberg TJ, Willner AE. Demonstration of optical multicasting using Kerr frequency comb lines. OPTICS LETTERS 2016; 41:3876-3879. [PMID: 27519112 DOI: 10.1364/ol.41.003876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We experimentally demonstrate optical multicasting using Kerr frequency combs generated from a Si3N4 microresonator. We obtain Kerr combs in two states with different noise properties by varying the pump wavelength in the resonator and investigate the effect of Kerr combs on multicasting. Seven-fold multicasting of 20 Gbaud quadrature phase-shift-keyed signals and four-fold multicasting of 16-quadrature amplitude modulation signals have been achieved when low-phase-noise combs are input into a periodically poled lithium niobate waveguide. In addition, we find that the wavelength conversion efficiency in the PPLN waveguide for chaotic combs with high noise is similar to that for low-noise combs, while the signal quality of the multicast copy is significantly degraded.
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129
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Kuse N, Schibli TR, Fermann ME. Low noise electro-optic comb generation by fully stabilizing to a mode-locked fiber comb. OPTICS EXPRESS 2016; 24:16884-16893. [PMID: 27464140 DOI: 10.1364/oe.24.016884] [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
A fully stabilized EO comb is demonstrated by phase locking the two degrees of freedom of an EO comb to a low noise mode-locked fiber comb. Division/magnification of residual phase noise of locked beats is observed by measuring an out-of-loop beat. By phase locking the 200 th harmonics of the EO comb and a driving cw frequency to a fiber comb, a record low phase noise EO comb across +/- 200 harmonics (from 1544.8 nm to 1577.3 nm) is demonstrated.
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130
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Bian D, Chen S, Lei X, Qin G, Chen Z. Design of a polymer-filled silicon nitride strip/slot asymmetric hybrid waveguide for realizing both flat dispersion and athermal operation. APPLIED OPTICS 2016; 55:4827-4832. [PMID: 27409106 DOI: 10.1364/ao.55.004827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
An asymmetric strip/slot hybrid silicon nitride waveguide is designed to simultaneously realize athermal operation and flat dispersion. The slot filling and upper cladding materials are negative thermal-optical coefficient (TOC), low refractive index polyurethane acrylate, while the left and right cladding layers are positive TOC, high refractive index silicon nitride. With suitable waveguide parameter selection, an optimum strip/slot hybrid silicon nitride waveguide exhibits an effective TOC of 1.263×10-7/K at 1550 nm, flattened dispersion in the wavelength range from 1200 to 1800 nm with the maximum dispersion of 30.51 ps/(nm·km), and a minimum of 10.89 ps/(nm·km). The proposed hybrid waveguide has great potential in building up broadband athermal microresonator optical frequency combs.
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131
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Parra-Rivas P, Gomila D, Knobloch E, Coen S, Gelens L. Origin and stability of dark pulse Kerr combs in normal dispersion resonators. OPTICS LETTERS 2016; 41:2402-2405. [PMID: 27244374 DOI: 10.1364/ol.41.002402] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We analyze dark pulse Kerr frequency combs in optical resonators with normal group-velocity dispersion using the Lugiato-Lefever model. We show that in the time domain the combs correspond to interlocked switching waves between the upper and lower homogeneous states, and explain how this fact accounts for many of their experimentally observed properties. Modulational instability does not play any role in their existence. We provide a detailed map indicating for which parameters stable dark pulse Kerr combs can be found, and how they are destabilized for increasing values of frequency detuning.
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132
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Guo C, Che K, Xu H, Zhang P, Tang D, Ren C, Luo Z, Cai Z. Generation of optical frequency combs in a fiber-ring/microresonator laser system. OPTICS LETTERS 2016; 41:2576-2579. [PMID: 27244418 DOI: 10.1364/ol.41.002576] [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 propose and experimentally demonstrate a simple scheme for generating optical frequency combs (OFCs) in a fiber-ring/microresonator laser system. The ultrahigh Q whispering gallery mode microresonator is employed both as a mode reflection mirror to generate erbium lasing and as a Kerr-nonlinearity initiator that introduces optical parametric oscillation signals to form OFCs. By controlling the coupling position between the fiber taper and microresonator, optimizing the fiber polarization, as well as the pump power from a 974 nm laser diode (LD), versatile OFCs can be tuned out from single-wavelength states. The OFCs have single, multiple, or combined free spectral ranges. In addition, a Raman-gain-assisted OFC is also observed with a bandwidth of ∼230 nm. This LD-pumped and multifunctional laser system could find applications in precision spectroscopy, biochemical sensing, and optical fiber communication systems.
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133
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Bao C, Liao P, Zhang L, Yan Y, Cao Y, Xie G, Mohajerin-Ariaei A, Li L, Ziyadi M, Almaiman A, Kimerling LC, Michel J, Willner AE. Effect of a breather soliton in Kerr frequency combs on optical communication systems. OPTICS LETTERS 2016; 41:1764-1767. [PMID: 27082339 DOI: 10.1364/ol.41.001764] [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
In this study, we numerically investigate the effect of Kerr-comb-generated breather soliton pulses on optical communication systems. The breather soliton pulse amplitude and spectrum envelope oscillate periodically in time. Simulations show that the spectrum of each comb line in the breather soliton state has multiple sub-teeth due to the periodic oscillation of the comb spectrum. In the simulation, the comb output is modulated with different formats. We find that the sub-teeth distort quadrature phase-shift-keyed signals but have less of an effect on on-off-keyed signals.
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134
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Huang SW, Yang J, Yu M, McGuyer BH, Kwong DL, Zelevinsky T, Wong CW. A broadband chip-scale optical frequency synthesizer at 2.7 × 10(-16) relative uncertainty. SCIENCE ADVANCES 2016; 2:e1501489. [PMID: 27152341 PMCID: PMC4846450 DOI: 10.1126/sciadv.1501489] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 03/17/2016] [Indexed: 05/15/2023]
Abstract
Optical frequency combs-coherent light sources that connect optical frequencies with microwave oscillations-have become the enabling tool for precision spectroscopy, optical clockwork, and attosecond physics over the past decades. Current benchmark systems are self-referenced femtosecond mode-locked lasers, but Kerr nonlinear dynamics in high-Q solid-state microresonators has recently demonstrated promising features as alternative platforms. The advance not only fosters studies of chip-scale frequency metrology but also extends the realm of optical frequency combs. We report the full stabilization of chip-scale optical frequency combs. The microcomb's two degrees of freedom, one of the comb lines and the native 18-GHz comb spacing, are simultaneously phase-locked to known optical and microwave references. Active comb spacing stabilization improves long-term stability by six orders of magnitude, reaching a record instrument-limited residual instability of [Formula: see text]. Comparing 46 nitride frequency comb lines with a fiber laser frequency comb, we demonstrate the unprecedented microcomb tooth-to-tooth relative frequency uncertainty down to 50 mHz and 2.7 × 10(-16), heralding novel solid-state applications in precision spectroscopy, coherent communications, and astronomical spectrography.
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Affiliation(s)
- Shu-Wei Huang
- Mesoscopic Optics and Quantum Electronics Laboratory, University of California, Los Angeles, CA 90095, USA
- Corresponding author. E-mail: (S.-W.H.); (C.W.W.)
| | - Jinghui Yang
- Mesoscopic Optics and Quantum Electronics Laboratory, University of California, Los Angeles, CA 90095, USA
| | - Mingbin Yu
- Institute of Microelectronics, Agency for Science, Technology and Research (A*STAR), Singapore 117865, Singapore
| | - Bart H. McGuyer
- Department of Physics, Columbia University, New York, NY 10027, USA
| | - Dim-Lee Kwong
- Institute of Microelectronics, Agency for Science, Technology and Research (A*STAR), Singapore 117865, Singapore
| | - Tanya Zelevinsky
- Department of Physics, Columbia University, New York, NY 10027, USA
| | - Chee Wei Wong
- Mesoscopic Optics and Quantum Electronics Laboratory, University of California, Los Angeles, CA 90095, USA
- Corresponding author. E-mail: (S.-W.H.); (C.W.W.)
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135
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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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136
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Uvin S, Keyvaninia S, Lelarge F, Duan GH, Kuyken B, Roelkens G. Narrow line width frequency comb source based on an injection-locked III-V-on-silicon mode-locked laser. OPTICS EXPRESS 2016; 24:5277-5286. [PMID: 29092352 DOI: 10.1364/oe.24.005277] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this paper, we report the optical injection locking of an L-band (∼1580 nm) 4.7 GHz III-V-on-silicon mode-locked laser with a narrow line width continuous wave (CW) source. This technique allows us to reduce the MHz optical line width of the mode-locked laser longitudinal modes down to the line width of the source used for injection locking, 50 kHz. We show that more than 50 laser lines generated by the mode-locked laser are coherent with the narrow line width CW source. Two locking techniques are explored. In a first approach a hybrid mode-locked laser is injection-locked with a CW source. In a second approach, light from a modulated CW source is injected in a passively mode-locked laser cavity. The realization of such a frequency comb on a chip enables transceivers for high spectral efficiency optical communication.
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137
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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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138
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Webb KE, Jang JK, Anthony J, Coen S, Erkintalo M, Murdoch SG. Measurement of microresonator frequency comb coherence by spectral interferometry. OPTICS LETTERS 2016; 41:277-280. [PMID: 26766693 DOI: 10.1364/ol.41.000277] [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 experimentally investigate the spectral coherence of microresonator optical frequency combs. Specifically, we use a spectral interference method, typically used in the context of supercontinuum generation, to explore the variation of the magnitude of the complex degree of first-order coherence across the full comb bandwidth. We measure the coherence of two different frequency combs and observe wholly different coherence characteristics. In particular, we find that the observed dynamical regimes are similar to the stable and unstable modulation instability regimes reported in previous theoretical studies. Results from numerical simulations are found to be in good agreement with experimental observations. In addition to demonstrating a new technique to assess comb stability, our results provide strong experimental support for previous theoretical analyses.
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139
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Xue X, Xuan Y, Wang C, Wang PH, Liu Y, Niu B, Leaird DE, Qi M, Weiner AM. Thermal tuning of Kerr frequency combs in silicon nitride microring resonators. OPTICS EXPRESS 2016; 24:687-698. [PMID: 26832298 DOI: 10.1364/oe.24.000687] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Microresonator based Kerr frequency comb generation has many attractive features, including ultrabroad spectra, chip-level integration, and low power consumption. Achieving precise tuning control over the comb frequencies will be important for a number of practical applications, but has been little explored for microresonator combs. In this paper, we characterize the thermal tuning of a coherent Kerr frequency comb generated from an on-chip silicon nitride microring. When the microring temperature is changed by ~70 °C with an integrated microheater, the line spacing and center frequency of the comb are tuned respectively by -253 MHz (-3.57 MHz/°C) and by -175 GHz (-2.63 GHz/°C); the latter constitutes 75% of the comb line spacing. From these results we obtain a shift of 25 GHz (362.07 MHz/°C) in the comb carrier-envelope offset frequency. Numerical simulations are performed by taking into account the thermo-optic effects in the waveguide core and cladding. The temperature variation of the comb line spacing predicted from simulations is close to that observed in experiments. The time-dependent thermal response of the microheater based tuning scheme is characterized; time constants of 30.9 μs and 0.71 ms are observed.
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140
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Brasch V, Geiselmann M, Herr T, Lihachev G, Pfeiffer MHP, Gorodetsky ML, Kippenberg TJ. Photonic chip-based optical frequency comb using soliton Cherenkov radiation. Science 2015; 351:357-60. [PMID: 26721682 DOI: 10.1126/science.aad4811] [Citation(s) in RCA: 207] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 12/03/2015] [Indexed: 11/02/2022]
Abstract
Optical solitons are propagating pulses of light that retain their shape because nonlinearity and dispersion balance each other. In the presence of higher-order dispersion, optical solitons can emit dispersive waves via the process of soliton Cherenkov radiation. This process underlies supercontinuum generation and is of critical importance in frequency metrology. Using a continuous wave-pumped, dispersion-engineered, integrated silicon nitride microresonator, we generated continuously circulating temporal dissipative Kerr solitons. The presence of higher-order dispersion led to the emission of red-shifted soliton Cherenkov radiation. The output corresponds to a fully coherent optical frequency comb that spans two-thirds of an octave and whose phase we were able to stabilize to the sub-Hertz level. By preserving coherence over a broad spectral bandwidth, our device offers the opportunity to develop compact on-chip frequency combs for frequency metrology or spectroscopy.
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Affiliation(s)
- V Brasch
- École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - M Geiselmann
- École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - T Herr
- École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - G Lihachev
- Russian Quantum Center, Skolkovo 143025, Russia. Faculty of Physics, M. V. Lomonosov Moscow State University, Moscow 119991, Russia
| | - M H P Pfeiffer
- École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - M L Gorodetsky
- Russian Quantum Center, Skolkovo 143025, Russia. Faculty of Physics, M. V. Lomonosov Moscow State University, Moscow 119991, Russia
| | - T J Kippenberg
- École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
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141
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Dai J, Xu X, Wu Z, Dai Y, Yin F, Zhou Y, Li J, Xu K. Self-oscillating optical frequency comb generator based on an optoelectronic oscillator employing cascaded modulators. OPTICS EXPRESS 2015; 23:30014-30019. [PMID: 26698482 DOI: 10.1364/oe.23.030014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
An ultraflat self-oscillating optical frequency comb generator based on an optoelectronic oscillator employing cascaded modulators was proposed and experimentally demonstrated. By incorporating the optoelectronic oscillation loop with cascaded modulators into the optical frequency comb generator, 11 ultraflat comb lines would be generated, and the frequency spacing is equal to the oscillation frequency of the OEO. 10 and 12GHz optical frequency combs are demonstrated with the spectral power variation below 0.82dB and 0.93dB respectively. The corresponding spectral pure microwave source are also generated and evaluated. The corresponding single-sideband phase noise are as low as -122dBc/Hz and -115 dBc/Hz at 10 kHz offset frequency.
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142
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Coluccelli N, Cassinerio M, Gambetta A, Laporta P, Galzerano G. Frequency-noise measurements of optical frequency combs by multiple fringe-side discriminator. Sci Rep 2015; 5:16338. [PMID: 26548900 PMCID: PMC4637836 DOI: 10.1038/srep16338] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 10/14/2015] [Indexed: 01/16/2023] Open
Abstract
The frequency noise of an optical frequency comb is routinely measured through the hetherodyne beat of one comb tooth against a stable continuous-wave laser. After frequency-to-voltage conversion, the beatnote is sent to a spectrum analyzer to retrive the power spectral density of the frequency noise. Because narrow-linewidth continuous-wave lasers are available only at certain wavelengths, heterodyning the comb tooth can be challenging. We present a new technique for direct characterization of the frequency noise of an optical frequency comb, requiring no supplementary reference lasers and easily applicable in all spectral regions from the terahertz to the ultraviolet. The technique is based on the combination of a low finesse Fabry-Perot resonator and the so-called “fringe-side locking” method, usually adopted to characterize the spectral purity of single-frequency lasers, here generalized to optical frequency combs. The effectiveness of this technique is demonstrated with an Er-fiber comb source across the wavelength range from 1 to 2 μm.
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Affiliation(s)
- Nicola Coluccelli
- Dipartimento di Fisica - Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.,Istituto di Fotonica e Nanotecnologie - CNR, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Marco Cassinerio
- Dipartimento di Fisica - Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.,Istituto di Fotonica e Nanotecnologie - CNR, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Alessio Gambetta
- Dipartimento di Fisica - Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.,Istituto di Fotonica e Nanotecnologie - CNR, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Paolo Laporta
- Dipartimento di Fisica - Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.,Istituto di Fotonica e Nanotecnologie - CNR, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Gianluca Galzerano
- Dipartimento di Fisica - Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.,Istituto di Fotonica e Nanotecnologie - CNR, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
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143
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Calò C, Vujicic V, Watts R, Browning C, Merghem K, Panapakkam V, Lelarge F, Martinez A, Benkelfat BE, Ramdane A, Barry LP. Single-section quantum well mode-locked laser for 400 Gb/s SSB-OFDM transmission. OPTICS EXPRESS 2015; 23:26442-26449. [PMID: 26480157 DOI: 10.1364/oe.23.026442] [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
Successful use of a single-section quantum well (QW) passively mode-locked laser (MLL) as a comb source for optical interconnects is demonstrated for the first time. Sixteen comb lines spaced by 37.6 GHz are modulated using 25 Gb/s compatible single sideband orthogonal frequency division multiplexed (SSB-OFDM) signals and transmitted over 50 km of standard single-mode fiber with bit error ratio below the 7% forward error correction limit. The system performance, analyzed on the basis of the relative intensity noise of the device, reveal the suitability of single-section QW MLLs as inexpensive comb sources for inter- and intra-data center communication scenarios.
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144
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Huang SW, Yang J, Lim J, Zhou H, Yu M, Kwong DL, Wong CW. A low-phase-noise 18 GHz Kerr frequency microcomb phase-locked over 65 THz. Sci Rep 2015; 5:13355. [PMID: 26311406 PMCID: PMC4550847 DOI: 10.1038/srep13355] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 07/23/2015] [Indexed: 11/27/2022] Open
Abstract
Laser frequency combs are coherent light sources that simultaneously provide pristine frequency spacings for precision metrology and the fundamental basis for ultrafast and attosecond sciences. Recently, nonlinear parametric conversion in high-Q microresonators has been suggested as an alternative platform for optical frequency combs, though almost all in 100 GHz frequencies or more. Here we report a low-phase-noise on-chip Kerr frequency comb with mode spacing compatible with high-speed silicon optoelectronics. The waveguide cross-section of the silicon nitride spiral resonator is designed to possess small and flattened group velocity dispersion, so that the Kerr frequency comb contains a record-high number of 3,600 phase-locked comb lines. We study the single-sideband phase noise as well as the long-term frequency stability and report the lowest phase noise floor achieved to date with -130 dBc/Hz at 1 MHz offset for the 18 GHz Kerr comb oscillator, along with feedback stabilization to achieve frequency Allan deviations of 7 × 10(-11) in 1 s. The reported system is a promising compact platform for achieving self-referenced Kerr frequency combs and also for high-capacity coherent communication architectures.
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Affiliation(s)
- S.-W. Huang
- Mesoscopic Optics and Quantum Electronics Laboratory, University of California, Los Angeles, CA, USA
- Optical Nanostructures Laboratory, Center for Integrated Science and Engineering, Solid-State Science and Engineering, and Mechanical Engineering, Columbia University, New York, NY, USA
| | - J. Yang
- Mesoscopic Optics and Quantum Electronics Laboratory, University of California, Los Angeles, CA, USA
- Optical Nanostructures Laboratory, Center for Integrated Science and Engineering, Solid-State Science and Engineering, and Mechanical Engineering, Columbia University, New York, NY, USA
| | - J. Lim
- Mesoscopic Optics and Quantum Electronics Laboratory, University of California, Los Angeles, CA, USA
| | - H. Zhou
- University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - M. Yu
- Institute of Microelectronics, Singapore, Singapore
| | - D.-L. Kwong
- Institute of Microelectronics, Singapore, Singapore
| | - C. W. Wong
- Mesoscopic Optics and Quantum Electronics Laboratory, University of California, Los Angeles, CA, USA
- Optical Nanostructures Laboratory, Center for Integrated Science and Engineering, Solid-State Science and Engineering, and Mechanical Engineering, Columbia University, New York, NY, USA
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145
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Liang W, Eliyahu D, Ilchenko VS, Savchenkov AA, Matsko AB, Seidel D, Maleki L. High spectral purity Kerr frequency comb radio frequency photonic oscillator. Nat Commun 2015; 6:7957. [PMID: 26260955 PMCID: PMC4918344 DOI: 10.1038/ncomms8957] [Citation(s) in RCA: 125] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 07/01/2015] [Indexed: 12/02/2022] Open
Abstract
Femtosecond laser-based generation of radio frequency signals has produced astonishing improvements in achievable spectral purity, one of the basic features characterizing the performance of an radio frequency oscillator. Kerr frequency combs hold promise for transforming these lab-scale oscillators to chip-scale level. In this work we demonstrate a miniature 10 GHz radio frequency photonic oscillator characterized with phase noise better than -60 dBc Hz(-1) at 10 Hz, -90 dBc Hz(-1) at 100 Hz and -170 dBc Hz(-1) at 10 MHz. The frequency stability of this device, as represented by Allan deviation measurements, is at the level of 10(-10) at 1-100 s integration time-orders of magnitude better than existing radio frequency photonic devices of similar size, weight and power consumption.
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Affiliation(s)
- W. Liang
- OEwaves Inc., 465 North Halstead Street, Suite 140, Pasadena, California 91107, USA
| | - D. Eliyahu
- OEwaves Inc., 465 North Halstead Street, Suite 140, Pasadena, California 91107, USA
| | - V. S. Ilchenko
- OEwaves Inc., 465 North Halstead Street, Suite 140, Pasadena, California 91107, USA
| | - A. A. Savchenkov
- OEwaves Inc., 465 North Halstead Street, Suite 140, Pasadena, California 91107, USA
| | - A. B. Matsko
- OEwaves Inc., 465 North Halstead Street, Suite 140, Pasadena, California 91107, USA
| | - D. Seidel
- OEwaves Inc., 465 North Halstead Street, Suite 140, Pasadena, California 91107, USA
| | - L. Maleki
- OEwaves Inc., 465 North Halstead Street, Suite 140, Pasadena, California 91107, USA
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146
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Miller SA, Okawachi Y, Ramelow S, Luke K, Dutt A, Farsi A, Gaeta AL, Lipson M. Tunable frequency combs based on dual microring resonators. OPTICS EXPRESS 2015; 23:21527-21540. [PMID: 26367998 DOI: 10.1364/oe.23.021527] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In order to achieve efficient parametric frequency comb generation in microresonators, external control of coupling between the cavity and the bus waveguide is necessary. However, for passive monolithically integrated structures, the coupling gap is fixed and cannot be externally controlled, making tuning the coupling inherently challenging. We design a dual-cavity coupled microresonator structure in which tuning one ring resonance frequency induces a change in the overall cavity coupling condition. We demonstrate wide extinction tunability with high efficiency by engineering the ring coupling conditions. Additionally, we note a distinct dispersion tunability resulting from coupling two cavities of slightly different path lengths, and present a new method of modal dispersion engineering. Our fabricated devices consist of two coupled high quality factor silicon nitride microresonators, where the extinction ratio of the resonances can be controlled using integrated microheaters. Using this extinction tunability, we optimize comb generation efficiency as well as provide tunability for avoiding higher-order mode-crossings, known for degrading comb generation. The device is able to provide a 110-fold improvement in the comb generation efficiency. Finally, we demonstrate open eye diagrams using low-noise phase-locked comb lines as a wavelength-division multiplexing channel.
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147
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Gui C, Li C, Yang Q, Wang J. Demonstration of terabit-scale data transmission in silicon vertical slot waveguides. OPTICS EXPRESS 2015; 23:9736-9745. [PMID: 25969012 DOI: 10.1364/oe.23.009736] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We design and fabricate silicon vertical slot waveguides for terabit-scale data transmission. The designed silicon photonic device is composed of apodized grating couplers, strip waveguides, strip-to-slot/slot-to-strip mode converters, and slot waveguide. Tight light confinement in the nano-scale air slot region is achieved in the silicon vertical slot waveguide which features relatively lower nonlinearity compared to silicon strip waveguide. Using the fabricated silicon photonic devices, we first demonstrate ultra-wide bandwidth 1.8-Tbit/s data transmission through a 2-mm-long silicon vertical slot waveguide using 161 wavelength-division multiplexing (WDM) channels each carrying 11.2-Gbit/s orthogonal frequency-division multiplexing (OFDM) 16-ary quadrature amplitude modulation (16-QAM) signal. All 161 WDM channels achieve bit-error rate (BER) less than 1e-3 after on-chip data transmission. We further demonstrate terabit-scale data transmission through four silicon vertical slot waveguides with different lengths (1 mm, 2 mm, 3.1 mm, 12.2 mm). The optical signal-to-noise ratio (OSNR) penalties of data transmission through four silicon vertical slot waveguides are 1, 2, 3.2 and 4.5 dB at a BER of 1e-3, respectively. The obtained results indicate that the presented silicon vertical slot waveguide might be an alternative promising candidate facilitating chip-scale high-speed optical interconnections.
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148
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Lin G, Martinenghi R, Diallo S, Saleh K, Coillet A, Chembo YK. Spectro-temporal dynamics of Kerr combs with parametric seeding. APPLIED OPTICS 2015; 54:2407-2412. [PMID: 25968529 DOI: 10.1364/ao.54.002407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 02/17/2015] [Indexed: 06/04/2023]
Abstract
We report a joint theoretical and experimental investigation of the parametric seeding of a primary Kerr optical frequency comb. Electro-optic modulation sidebands matching multiple free-spectral ranges of an ultrahigh-Q millimeter-size magnesium fluoride disk resonator are used as seed signals. These seed signals interact through four-wave mixing with the spectral components of a stable primary comb and give rise to complex spectro-temporal patterns. We show that the new frequency combs feature multiscale frequency spacing, with major frequency gaps in the order of a few hundred gigahertz, and minor frequency spacing in the order of a few tens of gigahertz. The experimental results are in agreement with numerical simulations using the Lugiato-Lefever equation. We expect such versatile and coherent optical frequency combs to have potential applications in optical communications systems where frequency management assigns predefined spectral windows at the emitter stage.
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149
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Krückel CJ, Torres-Company V, Andrekson PA, Spencer DT, Bauters JF, Heck MJR, Bowers JE. Continuous wave-pumped wavelength conversion in low-loss silicon nitride waveguides. OPTICS LETTERS 2015; 40:875-878. [PMID: 25768135 DOI: 10.1364/ol.40.000875] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this Letter we introduce a complementary metal-oxide semiconductor (CMOS)-compatible low-loss Si3N4 waveguide platform for nonlinear integrated optics. The waveguide has a moderate nonlinear coefficient of 285 W/km, but the achieved propagation loss of only 0.06 dB/cm and the ability to handle high optical power facilitate an optimal waveguide length for wavelength conversion. We observe a constant quadratic dependence of the four-wave mixing (FWM) process on the continuous-wave (CW) pump when operating in the C-band, which indicates that the waveguide has negligible high-power constraints owing to nonlinear losses. We achieve a conversion efficiency of -26.1 dB and idler power generation of -19.6 dBm. With these characteristics, we present for the first time, to the best of our knowledge, CW-pumped data conversion in a non-resonant Si3N4 waveguide.
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150
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Pfeifle J, Coillet A, Henriet R, Saleh K, Schindler P, Weimann C, Freude W, Balakireva IV, Larger L, Koos C, Chembo YK. Optimally coherent Kerr combs generated with crystalline whispering gallery mode resonators for ultrahigh capacity fiber communications. PHYSICAL REVIEW LETTERS 2015; 114:093902. [PMID: 25793816 DOI: 10.1103/physrevlett.114.093902] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Indexed: 06/04/2023]
Abstract
Optical Kerr frequency combs are known to be effective coherent multiwavelength sources for ultrahigh capacity fiber communications. These combs are the frequency-domain counterparts of a wide variety of spatiotemporal dissipative structures, such as cavity solitons, chaos, or Turing patterns (rolls). In this Letter, we demonstrate that Turing patterns, which correspond to the so-called primary combs in the spectral domain, are optimally coherent in the sense that for the same pump power they provide the most robust carriers for coherent data transmission in fiber communications using advanced modulation formats. Our model is based on a stochastic Lugiato-Lefever equation which accounts for laser pump frequency jitter and amplified spontaneous emission noise induced by the erbium-doped fiber amplifier. Using crystalline whispering-gallery-mode resonators with quality factor Q∼10^{9} for the comb generation, we show that when the noise is accounted for, the coherence of a primary comb is significantly higher than the coherence of their solitonic or chaotic counterparts for the same pump power. In order to confirm this theoretical finding, we perform an optical fiber transmission experiment using advanced modulation formats, and we show that the coherence of the primary comb is high enough to enable data transmission of up to 144 Gbit/s per comb line, the highest value achieved with a Kerr comb so far. This performance evidences that compact crystalline photonic systems have the potential to play a key role in a new generation of coherent fiber communication networks, alongside fully integrated systems.
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Affiliation(s)
- Joerg Pfeifle
- Institute of Photonics and Quantum Electronics (IPQ), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Aurélien Coillet
- FEMTO-ST Institute (CNRS UMR6174), Optics Department, 15B Avenue des Montboucons, 25030 Besançon cedex, France
| | - Rémi Henriet
- FEMTO-ST Institute (CNRS UMR6174), Optics Department, 15B Avenue des Montboucons, 25030 Besançon cedex, France
| | - Khaldoun Saleh
- FEMTO-ST Institute (CNRS UMR6174), Optics Department, 15B Avenue des Montboucons, 25030 Besançon cedex, France
| | - Philipp Schindler
- Institute of Photonics and Quantum Electronics (IPQ), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Claudius Weimann
- Institute of Photonics and Quantum Electronics (IPQ), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Wolfgang Freude
- Institute of Photonics and Quantum Electronics (IPQ), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Irina V Balakireva
- FEMTO-ST Institute (CNRS UMR6174), Optics Department, 15B Avenue des Montboucons, 25030 Besançon cedex, France
| | - Laurent Larger
- FEMTO-ST Institute (CNRS UMR6174), Optics Department, 15B Avenue des Montboucons, 25030 Besançon cedex, France
| | - Christian Koos
- Institute of Photonics and Quantum Electronics (IPQ), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Yanne K Chembo
- FEMTO-ST Institute (CNRS UMR6174), Optics Department, 15B Avenue des Montboucons, 25030 Besançon cedex, France
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