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Correlations of chaotic light in Kerr microresonators

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Correlations of chaotic light in Kerr microresonators

Conference on Lasers and Electro-Optics (CLEO)

作者： Ze Wang Kai-Xuan Zhu Hao-Jing Chen Lu Yao Qi-Huang Gong Qi-Fan Yang State Key Laboratory for Artificial Microstructure and Mesoscopic Physics and Frontiers Science Center for Nano-Optoelectronics School of Physics Peking University Beijing China Collaborative Innovation Center of Extreme Optics Shanxi University Taiyuan China Peking University Yangtze Delta Institute of Optoelectronics Nantong Jiangsu China

We experimentally investigate the dynamics of dissipative chaotic modulational instability in Kerr microresonators. Correlations of these waveforms are revealed in both temporal and spectral domain.

ISBN: (纸本)9781957171258

We experimentally investigate the dynamics of dissipative chaotic modulational instability in Kerr microresonators. Correlations of these waveforms are revealed in both temporal and spectral domain.

关键词： Fiber optic couplers Frequency combs Heterodyne detection Microresonators Modulational instabilities Silica fibers

Broadband microwave-rate dark pulse microcombs in dissipation-engineered LiNbO3 microresonators

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arXiv 2024年

作者： Lv, Xiaomin Nie, Binbin Yang, Chen Ma, Rui Wang, Ze Liu, Yanwu Jin, Xing Zhu, Kaixuan Chen, Zhenyu Qian, Du Zhang, Guanyu Lv, Guowei Gong, Qihuang Bo, Fang Yang, Qi-Fan State Key Laboratory for Artificial Microstructure and Mesoscopic Physics Frontiers Science Center for Nano-optoelectronics School of Physics Peking University Beijing100871 China Hefei National Laboratory Hefei230088 China Nankai University Tianjin300071 China Collaborative Innovation Center of Extreme Optics Shanxi University Taiyuan030006 China Peking University Yangtze Delta Institute of Optoelectronics Nantong226010 China

Kerr microcombs generated in optical microresonators provide broadband light sources bridging optical and microwave signals. Their translation to thin-film lithium niobate unlocks second-order nonlinear optical interfaces such as electro-optic modulation and frequency doubling for completing comb functionalities. However, the strong Raman response of LiNbO3 has complicated the formation of Kerr microcombs. Until now, dark pulse microcombs, requiring a double balance between Kerr nonlinearity and normal group velocity dispersion as well as gain and loss, have remained elusive in LiNbO3 microresonators. Here, by incorporating dissipation engineering, we demonstrate dark pulse microcombs with 25 GHz repetition frequency and 200 nm span in a high-Q LiNbO3 microresonator. Resonances near the Raman-active wavelengths are strongly damped by controlling phase-matching conditions of a specially designed pulley coupler. The coherence and tunability of the dark pulse microcombs are also investigated. Our work provides a solution to realize high-power microcombs operating at microwave rates on LiNbO3 chips, promising new opportunities for the monolithic integration of applications spanning communication to microwave photonics. Copyright © 2024, The Authors. All rights reserved.

关键词： Niobium compounds

Inverse design of coherent supercontinuum generation using free-form nanophotonic waveguides

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arXiv 2023年

作者： Lee, Chia-Yi Liu, Yanwu Cheng, Yinke Lao, Chenghao Gong, Qihuang Yang, Qi-Fan State Key Laboratory for Artificial Microstructure and Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics School of Physics Peking University Beijing100871 China Collaborative Innovation Center of Extreme Optics Shanxi University Taiyuan China Peking University Yangtze Delta Institute of Optoelectronics Jiangsu Nantong226010 China

Many key functionalities of optical frequency combs such as self-referencing and broad spectral access rely on coherent supercontinuum generation (SCG). While nanophotonic waveguides have emerged as a compact and power-efficient platform for SCG, their geometric degrees of freedom have not been fully utilized due to the underlying nonlinear and stochastic physics. Here, we introduce inverse design to unlock free-form waveguides for coherent SCG. The efficacy of our design is numerically and experimentally demonstrated on Si3N4 waveguides, producing flat and coherent spectra from visible to mid-infrared wavelengths. Our work has direct applications in developing chip-based broadband light sources for spectroscopy, metrology, and sensing across multiple spectral regimes. Copyright © 2023, The Authors. All rights reserved.

关键词： Light sources

Spin relaxation induced by interfacial effects in GaN/Al_(0.25) Ga_(0.75) N heterostructures

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Fundamental Research 2021年第6期1卷 656-660页

作者： Shixiong Zhang Ning Tang Xiaoyue Zhang Xingchen Liu Lei Fu Yunfan Zhang Teng Fan Zhenhao Sun Fentao Wang Weikun Ge Bo Shen State Key Laboratory of Artificial Microstructure and Mesoscopic Physics School of PhysicsPeking UniversityBeijing 100871China Frontiers Science Center for Nano-optoelectronics and Collaboration Innovation Center of Quantum Matter Peking UniversityBeijing 100871China Peking University Yangtze Delta Institute of Optoelectronics Nantong 226010China

Spin relaxation induced by the interfacial effects in GaN/Al_(0.25) Ga_(0.75) N heterostructures was carefully investigated using a photon-energy-dependent time-resolved Kerr rotation *** existence of the interfacial localized states with potential fluctuations at the GaN/AlGaN heterointerface leads to photoluminescence peaks showing blue and S-shaped shifts owing to the excitation power and temperature,*** electrons in the localized states show a spin relaxation time longer than 1 ns because of the suppression of the D’yakonov-Perel’(DP)scattering,while the spin relaxation time of free electrons was approximately only 10 ps because of the giant Rashba spin-orbit coupling induced by the interfacial polarization field under the framework of the DP scattering ***,it is found that the high electron mobility at the heterointerface results in a long spin diffusion length of 300 nm at high temperatures,which is promising for the development of GaN-based spintronic devices.

关键词： GaN/AlGaN heterointerface Two-dimensional electron gas Interfacial localized state Spin dynamics Polarization field

Review on the Progress of AlGaN-based Ultraviolet Light-Emitting Diodes

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Fundamental Research 2021年第6期1卷 717-734页

作者： Yuxuan Chen Jianwei Ben Fujun Xu Jinchai Li Yang Chen Xiaojuan Sun Dabing Li State Key Laboratory of Luminescence and Applications Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Artificial Microstructure and Mesoscopic Physics School of PhysicsPeking UniversityBeijing 100871China Fujian Key Laboratory of Semiconductor Materials and Applications CI Center for OSEDCollege of Physical Science and TechnologyXiamen UniversityXiamen 361005China

AlGaN-based materials have exhibited considerable potential for fabricating ultraviolet(UV)light-emitting diodes(LEDs)owing to their direct,wide,and adjustable energy ***-based devices have extensive appli-cability owing to their stable physico-chemical *** decades of research effort,significant progress has been achieved in enhancing the working efficiency of AlGaN-based LEDs by optimizing the crystalline qual-ity,doping efficiency,and device *** this review,methods to obtain high-quality AlGaN-based materials,achieve high doping efficiency,and design UV-LED structures are summarized and ***,the issues that need to be addressed in AlGaN-based UV-LED devices are highlighted.

关键词： AlGaN Growth of AlGaN-based material Doping UV-LED

High-Performance SAW Resonators Based on Single-crystalline a-Plane AlN Thin Films on Sapphire Substrates

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High-Performance SAW Resonators Based on Single-crystalline ...

IEEE Symposium (IUS) Ultrasonics

作者： Xiaoli Fang Ye Yuan Shibin Zhang Pengcheng Zheng Yanda Ji Liping Zhang Jinbo Wu Xuedi Tian Hulin Yao Xinqiang Wang Xin Ou National Key Laboratory of Materials for Integrated Circuits Shanghai Institute of Microsystem and Information Technology Shanghai China The Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Beijing China Songshan Lake Materials Laboratory Dongguan China Department of Applied Physics College of Physics MIIT Key Laboratory of Aerospace Information Materials and Physics Nanjing University of Aeronautics and Astronautics Nanjing China State Key Laboratory of Artificial Microstructure and Mesoscopic Physics School of Physics Peking University Beijing China

This work reports on high-performance surface acoustic wave (SAW) piezoelectric resonators based on a-plane Aluminum nitride (AlN) thin films. Rayleigh SAW resonators with different in-plane orientations on AlN thin film were investigated. The resonator with in-plane orientation parallel to the C-axis of the AlN thin film shows better performance, exhibiting an excellent maximum Bode_Q (Q max ) of 3731 at 2.38 GHz, an impedance ratio of 39 dB, and a high phase velocity of about 5700 m/s. The fitted first-order temperature coefficient of frequency (TCF) values for the resonant frequency (f r ) and anti-resonant frequency (f a ) are −46.7 ppm/°C and −46.6 ppm/°C at the temperature range of 25°C to 145°C, respectively. More importantly, the Q max of the a-plane AlN thin film based SAW resonator is maintained well at 2682 even at 145°C. These results demonstrate that the a-plane AlN is a promising platform to achieve high-velocity, low-loss resonators and narrow band filters.

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Probing spin textures in atomically thin CrSBr through tunneling magnetoresistance

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arXiv 2024年

作者： Liu, Ziqi Zhu, Chengfeng Gao, Yuchen Chen, Zuxin Gu, Pingfan Ye, Yu State Key Laboratory for Artificial Microstructure & Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics School of Physics Peking University Beijing100871 China School of Semiconductor Science and Technology South China Normal University Foshan528225 China Yangtze Delta Institute of Optoelectronics Peking University Jiangsu Nantong226010 China Liaoning Academy of Materials Shenyang110167 China

The exploration of spin configurations and magnetoresistance in van der Waals magnetic semiconductors, particularly in the realm of thin-layer structures, holds paramount significance for the development of two-dimensional spintronic nanodevices. In this Letter, we conducted comprehensive magnetotransport measurements on a few-layer CrSBr using a vertical tunneling device configuration. Notably, our investigation revealed that tunneling magnetoresistance possesses a distinctive capability to discern spin configurations that would otherwise remain indistinguishable through alternative techniques such as photoluminescence. We observed the existence of energy-degenerate states exhibiting identical net magnetization and comparable spin configurations, which could be differentiated based on their rectification properties, reminiscent of a diode-like behavior at positive and negative bias voltages. Specifically, in devices comprising 5-layer CrSBr, we observed an intriguing positive magnetoresistive state when subjected to an in-plane magnetic field along the b-axis. To gain a deeper understanding of the underlying mechanisms, we developed a one-dimensional linear chain model that successfully computed the magnetic state, thereby elucidating the underlying spin configurations responsible for the observed transport phenomena. These findings not only provide novel perspectives into the intricate spin textures of two-dimensional CrSBr but also underscore the sensitivity of tunneling as a probing technique for investigating the magnetic order in van der Waals materials. © 2024, CC0.

关键词： Van der Waals forces

Efficient InGaN-based Red Light-Emitting Diodes by Modulating Trench Defects

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arXiv 2023年

作者： Pan, Zuojian Chen, Zhizhong Zhang, Haodong Yang, Han Deng, Chuhan Dong, Boyan Wang, Daqi Li, Yuchen Lin, Hai Chen, Weihua Jiao, Fei Kang, Xiangning Jia, Chuanyu Liang, Zhiwen Wang, Qi Zhang, Guoyi Shen, Bo State Key Laboratory for Artificial Microstructure and Mesoscopic Physics School of Physics Peking University Beijing100871 China Dongguan Institute of Optoelectronics Peking University Dongguan523808 China Yangtze Delta Institute of Optoelectronics Peking University Nantong226000 China State Key Laboratory of Nuclear Physics and Technology School of Physics Peking University Beijing100871 China School of International Academy of Microelectronics Dongguan University of Technology Dongguan523000 China

Trench defects in multi-quantum wells (MQWs) have been considered as flawed structures that severely degraded the internal quantum efficiency (IQE) of light-emitting diodes (LEDs) in the past. In this research, trench defects are innovatively utilized to enhance the efficiency of red InGaN LEDs. Specifically, dual-color MQWs structures were applied to modulate trench defects. The upper red MQWs, grown on top of green MQWs with a high density of trench defects, exhibit a significant wavelength redshift of 68 nm and approximately 6-fold luminescence enhancement compared to those without intentionally introduced trench defects. Red InGaN LEDs with an IQE of 16.4% are achieved with this epitaxy growth strategy. Such wavelength redshift is attributed to the more indium incorporation due to the strain relaxation effect of trench defects. Moreover, the luminescence enhancement originates from the strong emission of the red MQWs inside trench defects, mainly attributed to strain relaxation and defect shielding by the wide and deep trenches. Achieving red emission by modulating trench defects is simple and reproducible without requiring additional substrate designs, which provides a novel way toward high-efficiency red InGaN LEDs. © 2023, CC BY-NC-ND.

关键词： Semiconductor alloys

Magnetoresistance signature of two-dimensional electronic states in Co3Sn2S2

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Physical Review B 2023年第8期107卷 085203-085203页

作者： Jiaji Zhao Bingyan Jiang Shen Zhang Lujunyu Wang Enke Liu Zhilin Li Xiaosong Wu State Key Laboratory for Artificial Microstructure and Mesoscopic Physics Frontiers Science Center for Nano-optoelectronics Peking University Beijing 100871 China Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China Collaborative Innovation Center of Quantum Matter Beijing 100871 China Shenzhen Institute for Quantum Science and Engineering Southern University of Science and Technology Shenzhen 518055 China Peking University Yangtze Delta Institute of Optoelectronics Nantong 226010 Jiangsu China

Two-dimensional (2D) Dirac bands and flat bands are characteristics of a kagome lattice. However, experimental studies on their electrical transport are few, because three-dimensional (3D) bulk bands of kagome materials, consisting of stacked 2D kagome layers, dominate the transport. We report a magnetoresistance (MR) study of a kagome material, Co3Sn2S2. Based on analysis of the temperature, magnetic field, and field angle dependence of the resistivity, we obtain a complete anatomy of MR. Besides a magnon MR, a chirality-dependent MR, and a chiral-anomaly-induced MR, the most intriguing feature is an orbital MR that scales only with the out-of-plane field, which strongly indicates its 2D nature. We attribute it to the Dirac band of the kagome lattice.

关键词： Angular-dependent magnetoresistance Magnetism Kagome lattice Topological materials Transport techniques