Article
Optics
The Anh Nguyen, Ming-Chang M. Lee
Summary: An ultra-thin Si-padded Si3N4 waveguide was proposed, with a very thin Si slab and a Si3N4 strip separated by a SiO2 layer. The measured waveguide propagation loss is low at 0.055 dB/cm, and the bending loss is within an acceptable range. Part of the waveguide mode is distributed in the Si slab, showing potential for low-loss and high-speed photonic integrated circuits.
Article
Chemistry, Multidisciplinary
Dawson B. Bonneville, Jeremy W. Miller, Caitlin Smyth, Peter Mascher, Jonathan D. B. Bradley
Summary: The study reports on the deposition of high-optical quality silicon nitride thin films under low-temperature and low-pressure conditions using ECR-PECVD technology. The as-deposited films exhibit variable compositions with significant oxygen content and hydrogen incorporation.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Zhaoyi Li, Zuowen Fan, Jingjie Zhou, Qingyu Cong, Xianfeng Zeng, Yumei Zhang, Lianxi Jia
Summary: Silicon nitride is a material with great potential in silicon photonics due to its compatibility with CMOS processes and various advantages. However, the high stress generated during the deposition process restricts the thickness of the silicon nitride film on large wafers. In this study, we successfully fabricated a 400 nm-thick silicon nitride waveguide on an 8-inch wafer using a Damascene method and achieved low propagation losses at both 1550 nm and 1580 nm wavelengths.
APPLIED SCIENCES-BASEL
(2023)
Article
Multidisciplinary Sciences
Pei-Hsun Wang, Shang-Pu Wang, Nien-Lin Hou, Zong-Ren Yang, Wei-Hao Huang, Tien-Hsiang Lee
Summary: We demonstrate the manipulation of waveguide dispersion by lithographically patterning the polymer cladding on silicon nitride waveguide resonators. Both normal and anomalous dispersion can be achieved within the same waveguide dimension on an integrated photonic chip. This process has no impact on waveguide loss and quality factor, providing flexibility for designable dispersion on a universal photonic platform. Additionally, a relatively low dispersion is demonstrated by adjusting the coverage ratio of cladding, making zero-dispersive waveguide resonators possible.
SCIENTIFIC REPORTS
(2023)
Article
Optics
Alexander D. White, Geun Ho Ahn, Kasper Van Gasse, Ki Youl Yang, Lin Chang, John E. Bowers, Jelena Vuckovic
Summary: This article demonstrates an integrated approach for passively isolating a continuous-wave laser using the non-reciprocal Kerr nonlinearity in ring resonators. By using silicon nitride as the model platform, the authors achieve single ring isolation of 17-23 dB with 1.8-5.5 dB insertion loss, and cascaded ring isolation of 35 dB with 5 dB insertion loss. They also demonstrate hybrid integration and isolation with a semiconductor laser chip using these devices.
Article
Optics
Bin Li, Donghao Li, Bo Tang, Peng Zhang, Yan Yang, Ruonan Liu, Ling Xie, Zhihua Li
Summary: Silicon nitride photonics offers a range of benefits for applications in tele/datacom, artificial intelligence, sensing, and bio-photonics. The low-loss silicon nitride waveguide technology complements silicon-on-insulator photonics by extending capabilities. Wafer-level silicon nitride waveguides with reduced stress were fabricated using a two-step deposition method. Line width compensation is required to correct deviations between single-stripe and multiple-stripe structures. Overall, the propagation losses in the C-band slightly decreased with width increase from 0.9 μm to 1 μm.
Article
Engineering, Electrical & Electronic
Martino Bernard, Luca Gemma, Davide Brunelli, Giovanni Paternoster, Mher Ghulinyan
Summary: We report on the design, fabrication, and characterization of a Silicon Nitride (SiN)-based integrated photonic chip in which the dielectric waveguides are coupled to photodetectors integrated homogeneously into the Silicon substrate. The photonic-electronic coupling was realized by a 3D inverse tapering of SiN waveguides.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Physics, Multidisciplinary
Haofan Yang, Jing Xu, Zhongfei Xiong, Xinda Lu, Ruo-Yang Zhang, Hanghang Li, Yuntian Chen, Shuang Zhang
Summary: The scattering immune propagation of light in topological photonic systems may revolutionize the design of integrated photonic circuits for information processing and communications. The spin-valley Hall effect (SVHE) is proposed as a way to expand topologically protected edge channels and enhance information multiplexing. An experimentally feasible platform based on coupled ring resonators mediated by optical Kerr nonlinearity is suggested to realize SVHE for light and achieve spin-valley photonics in optical communication systems.
PHYSICAL REVIEW LETTERS
(2021)
Article
Multidisciplinary Sciences
Xavier X. Chia, George F. R. Chen, Yanmei Cao, Peng Xing, Hongwei Gao, Doris K. T. Ng, Dawn T. H. Tan
Summary: Chemical vapor deposition-based growth techniques allow flexible design of CMOS compatible materials. Deuterated silicon-rich nitride films grown using plasma-enhanced chemical vapor deposition show good linear and nonlinear properties and eliminate Si-H and N-H related absorption. Films grown with SiD4 demonstrate improved performance compared to those grown with SiH4.
SCIENTIFIC REPORTS
(2022)
Article
Optics
Pei-Hsun Wang, Tien-Hsiang Lee, Wei-Hao Huang
Summary: A tapered bus-waveguide is used to enhance waveguide-to-cavity coupling through mass-productive, cost-effective i-line UV lithography. The enlarged overlap between the evanescent wave and waveguide resonator results in a coupling strength of silicon nitride waveguides that is 7 times stronger than conventional coupling. Strong over-coupling is achieved at a 400 nm gap and with a quality factor of approximately 105, without elongating the coupling length.
Article
Optics
Yuxin Liang, Zhihui LI, Shijia Fan, Jing Feng, Dapeng Liu, Haijun Liao, Zhonghua Yang, Junbo Feng, Naidi Cui
Summary: This work presents the design and fabrication of an ultra-low loss silicon nitride edge coupler for interfacing with a single-mode fiber. Unlike previous studies, the focus of this work is on the cladding structure. By optimizing the thickness of the up-cladding, adding air trenches, and slightly increasing the refractive index, efficient mode coupling is achieved.
Article
Optics
Toijam Sunder Meetei, Seong-Jin Son, Byeongchan Park, Yong-Tak Lee, Nan Ei Yu
Summary: In this paper, a systematic numerical investigation of the mode properties of a strip-loaded SRN-LNOI hybrid waveguide at 1550 nm wavelength using the full-vectorial finite difference method is presented. The effective refractive indices of the transverse electric and transverse magnetic modes of strip-loaded SRN-LN hybrid waveguides were analyzed considering the anisotropic nature of the lithium niobate (LN) crystal. The study discusses the single-mode condition, zero-birefringence, effective mode area, and power distribution in terms of the geometrical parameters of the strip-loaded SRN-LN hybrid waveguide.
Article
Optics
Cameron M. Naraine, Jocelyn N. Westwood-Bachman, Cameron Horvath, Mirwais Aktary, Andrew P. Knights, Jens H. Schmid, Pavel Cheben, Jonathan D. B. Bradley
Summary: Subwavelength grating (SWG) metamaterial waveguides and ring resonators on a silicon nitride platform are proposed and demonstrated. The SWG waveguide achieves a large overlap (53%) of the Bloch mode with the top cladding material, showing great potential for evanescent field sensing and light amplification. Fabricated using a commercial rapid turn-around silicon nitride prototyping foundry process, the devices have critical dimensions greater than 100 nm. Experimental characterization reveals excellent internal quality factor (2.11 x 10(5)) and low propagation loss (approximately 1.5 dB cm(-1)) in the C-band, surpassing silicon-based SWG ring resonators. These results demonstrate the promising prospects of SWG metamaterial structures for silicon nitride based photonic integrated circuits.
LASER & PHOTONICS REVIEWS
(2023)
Review
Physics, Multidisciplinary
Dawn T. H. Tan, D. K. T. Ng, J. W. Choi, E. Sahin, B-U Sohn, G. F. R. Chen, P. Xing, H. Gao, Y. Cao
Summary: This article reviews the recent progress in USRN-based nonlinear integrated optics devices, discussing their impacts such as high gain optical parametric amplification and observations of soliton effects in photonic waveguides. The future outlook of CMOS-compatible USRN-based nonlinear optics is also assessed.
ADVANCES IN PHYSICS-X
(2021)
Article
Materials Science, Ceramics
Yuting Zheng, Qinrui Zhang, Guanzhong Qiao, Junjun Wei, Jinlong Liu, Liangxian Chen, Kang An, Xiaotong Zhang, Haitao Ye, Haojun Zhou, Hongliang Tao, Yuhang Yin, Xiaoping Ouyang, Chengming Li
Summary: This study demonstrates the use of a SiNx dielectric layer to improve diamond nucleation and growth, reduce stress, and form Si-C(SiC)MIDLINE HORIZONTAL ELLIPSISSiMIDLINE HORIZONTAL ELLIPSISC (diamond) bond bridges on SiC wafers.
CERAMICS INTERNATIONAL
(2022)
Article
Optics
Oskar B. Helgason, Francisco R. Arteaga-Sierra, Zhichao Ye, Krishna Twayana, Peter A. Andrekson, Magnus Karlsson, Jochen Schroder, Victor Torres-Company
Summary: The study focuses on the nonlinear dynamics of photonic diatomic molecules in two linearly coupled microresonators, demonstrating the formation of self-enforcing solitary waves when a laser is tuned across a split energy level. The resulting microcomb is coherent, tunable, and reproducible, with high conversion efficiency and spectral flatness, making it suitable for applications in optical communications, spectroscopy, and astronomy.
Article
Engineering, Electrical & Electronic
Mikael Mazur, Myoung-Gyun Suh, Attila Fulop, Jochen Schroder, Victor Torres-Company, Magnus Karlsson, Kerry J. Vahala, Peter A. Andrekson
Summary: Spectral efficiency (SE) is a key metric for optical communication networks, and optical superchannels can maximize SE by efficiently utilizing available bandwidth and minimizing guard-bands between channels. Microcombs are a promising solution for low power superchannel laser sources that provide high signal quality, broadband waveforms, but their realization with sufficient line power, coherence, and line spacing compatible with electronic bandwidths is extremely challenging.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Optics
Zhichao Ye, Fuchuan Lei, Krishna Twayana, Marcello Girardi, Peter A. Andrekson, Victor Torres-Company
Summary: The generation of sub-50GHz soliton microcombs in dispersion-engineered silicon nitride microresonators has been achieved by implementing an optimized racetrack design, minimizing coupling to higher-order modes and reducing the footprint size significantly. These devices feature a statistical intrinsic quality factor of 19 million and have successfully generated soliton microcombs at repetition rates of 20.5 and 14.0 GHz. The fabrication process is entirely subtractive, allowing direct patterning on the silicon nitride film.
LASER & PHOTONICS REVIEWS
(2022)
Article
Optics
Israel Rebolledo-Salgado, Zhichao Ye, Simon Christensen, Fuchuan Lei, Krishna Twayana, Jochen Schroder, Martin Zelan, Victor Torres-Company
Summary: This study explores the use of high repetition rate picosecond pulses in Si3N4 waveguides for coherent spectral broadening, and demonstrates the formation of coherent supercontinuum spectrum using high energy pulses. These results offer a new prospect for coherent broadening using long duration pulses and replacing bulky optical components.
Article
Optics
Fuchuan Lei, Zhichao Ye, Victor Torres-Company
Summary: Thermal noise dominates the low-frequency region of optical phase noise in soliton microcombs, limiting applications. Laser cooling with a pump laser can mitigate this noise by simultaneously exciting two neighboring cavity modes from different families.
Article
Engineering, Electrical & Electronic
Ping Zhao, Zhichao Ye, Magnus Karlsson, Victor Torres-Company, Peter A. Andrekson
Summary: This paper reports a low-noise optical phase-sensitive amplifier (PSA) enabled by a single compact integrated silicon nitride photonic waveguide, which allows optical signal processing at different wavelengths. The experimental results show that silicon-nitride-based PSAs are promising for the next generation of broadband optical signal processing and communication systems.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Optics
J. Connor Skehan, Oskar B. Helgason, Jochen Schroeder, Victor Torres-Company, Peter A. Andrekson
Summary: This article demonstrates a method to generate a widely and arbitrarily tunable laser source with a very narrow linewidth, achieving a high power, high side mode suppression ratio output wave. The method is implemented across 1530 -1585 nm range and the prospects of extending its performance are discussed.
Review
Chemistry, Analytical
Krishna Twayana, Israel Rebolledo-Salgado, Ekaterina Deriushkina, Jochen Schroder, Magnus Karlsson, Victor Torres-Company
Summary: This review paper provides an overview of the latest advancements in linear interferometric techniques using laser frequency comb sources. Various techniques including Fourier transform spectroscopy, linear spectral interferometry and swept-wavelength interferometry are extensively discussed. The unique features enabled by laser frequency comb sources are demonstrated, along with specific applications in molecular spectroscopy, optical coherence tomography, and the characterization of photonic integrated devices and components. Lastly, the potential possibilities offered by advancements in chip-scale swept sources and frequency combs are explored.
Article
Optics
Krishna Twayana, Fuchuan Lei, Zhichao Ye, Israel Rebolledo-Salgado, Oskar B. Helgason, Magnus Karlsson, Victor Torres-Company
Summary: We report a linear heterodyne technique assisted by electro-optic downconversion that enables differential phase measurement of microcombs with unprecedented sensitivity and bandwidth coverage.
Article
Multidisciplinary Sciences
Fuchuan Lei, Zhichao Ye, Oskar B. Helgason, Attila Fulop, Marcello Girardi, Victor Torres-Company
Summary: The authors study the phase noise dynamics and linewidth of soliton microcombs and find that some comb lines can have less noise than the pump laser itself. This work not only provides insights into the physical limits of phase coherence in soliton microcombs but also demonstrates a new strategy for generating spectrally coherent light on chip.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
Fuchuan Lei, Zhichao Ye, Krishna Twayana, Yan Gao, Marcello Girardi, Oskar B. Helgason, Ping Zhao, Victor Torres-Company
Summary: Optical hyperparametric oscillation based on the third-order nonlinearity is a significant mechanism to generate coherent electromagnetic radiation and produce quantum states of light. Advances in dispersion-engineered high-Q microresonators have allowed for generating signal waves far from the pump and decreasing the oscillation power threshold. However, the efficiency and absolute power of the pump-to-signal conversion are limited by parasitic mode competition and the achievable cavity intrinsic Q to coupling Q ratio.
PHYSICAL REVIEW LETTERS
(2023)
Article
Optics
Kaiyi Wu, Nathan P. O'malley, Saleha Fatema, Cong Wang, Marcello Girardi, Mohammed S. Alshaykh, Zhichao Ye, Daniel E. Leaird, Minghao Qi, Victor Torres-Company, Andrew M. Weiner
Summary: Recent advances in Kerr microcombs could lead to future development of fully stabilized ultralow size, weight, and power consumption frequency combs. However, bandwidth/repetition rate trade-off has hindered the progress of Kerr microcombs. Despite exciting progress in dual-comb techniques for measuring THz repetition rates, the detection problem of carrier envelope offset frequency remains largely unresolved. This work demonstrates the simultaneous detection of electronically divided repetition rate and carrier envelope offset frequency using a Vernier dual-comb configuration, which could have significant implications in real-world applications of optical atomic clocks and microwave generators.
Article
Optics
Yan Gao, Fuchuan Lei, Marcello Girardi, Zhichao Ye, Raphael Van Laer, Victor Torres-Company, Jochen Schroder
Summary: Lithium niobate (LN) is a promising material for future complex photonic-electronic circuits. By fully etching LN waveguides, we have achieved a compact and ultralow-loss LN platform with great potential in future miniaturized multifunctional integration systems.
Article
Physics, Multidisciplinary
Israel Rebolledo-Salgado, Clara Quevedo-Galan, oskar Bjarki Helgason, Anton Loof, Zhichao Ye, Fuchuan Lei, Jochen Schroder, Martin Zelan, Victor Torres-Company
Summary: In this study, platicons microcombs are generated using photonic molecules, resulting in an engineered microcomb spectrum that closely resembles the ideal single microresonator case. The authors observe the coupling between the repetition rate of the platicon microcomb and the frequency of the pump laser, and demonstrate the application of this coupling in dual-comb interferometry. These results contribute to understanding dissipative structures in normal-dispersion microresonators and offer an alternative for applications such as spectroscopy and metrology.
COMMUNICATIONS PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
Ekaterina Deriushkina, Israel Rebolledo-Salgado, Mikael Mazur, Victor Torres-Company, Peter Andrekson, Jochen Schroeder, Magnus Karlsson
Summary: This paper presents an experimental scheme that combines swept-wavelength interferometry and dual-comb spectroscopy to overcome their limitations. By using a tunable laser source to sweep over the frequency comb spacing and capture all intermediate frequencies, full-field broadband measurements over 1.25 THz comb bandwidth with increased frequency resolution are demonstrated.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
