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
Chemistry, Analytical
Jihong Kim, Youngil Kim, Sung-Min Hong
Summary: In this study, we demonstrate the epitaxial growth of AlN thin films on Mo electrode/sapphire (0001) substrates. The highly ordered Mo thin films serve as templates for the epitaxial growth of AlN thin films by transferring the crystallographic information of the sapphire substrates. The orientation relationships among the AlN thin films, Mo thin films, and sapphire substrates are successfully defined.
Article
Optics
Chengli Wang, Zhiwei Fang, Ailun Yi, Bingcheng Yang, Zhe Wang, Liping Zhou, Chen Shen, Yifan Zhu, Yuan Zhou, Rui Bao, Zhongxu Li, Yang Chen, Kai Huang, Jiaxiang Zhang, Ya Cheng, Xin Ou
Summary: By experimenting with photonic microresonators on a 4H-silicon-carbide-on-insulator platform, a wide range of frequency conversion phenomena, including second-, third-, and fourth-harmonic generation, as well as cascaded Raman lasing, were observed under high-Q factors. Additionally, by engineering the dispersion properties of the SiC microresonator, broadband Kerr frequency combs covering from 1300 to 1700nm were achieved. This demonstration represents a significant milestone in the development of SiC photonic integrated devices.
LIGHT-SCIENCE & APPLICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Jack A. Smith, Henry Francis, Gabriele Navickaite, Michael J. Strain
Summary: This article presents a high-performance silicon nitride photonic integrated circuit platform that operates at visible wavelengths and is accessible through the commercial foundry, LIGENTEC. The article measures propagation losses across the visible spectrum from 450 nm to 850 nm. For wavelengths above 630 nm, the losses are <1 dB/cm in TE and <0.5 dB/cm in TM. In addition, sets of single mode waveguide-coupled ring resonators across three separate chips were tested and analyzed. The article provides an analysis of the loss and coupling, considering the bus-ring coupling gap and waveguide width. High confinement, low loss devices based on chip-scale silicon nitride are becoming increasingly important for the next generation of integrated optical devices operating at visible wavelengths.
OPTICAL MATERIALS EXPRESS
(2023)
Article
Chemistry, Physical
Fabi Zhang, Jin Zhang, Lijie Huang, Shangfeng Liu, Wei Luo, Junjie Kang, Zhiwen Liang, Jiakang Cao, Chenhui Zhang, Qi Wang, Ye Yuan
Summary: In this study, epitaxial semipolar (11-22) AlN was successfully prepared on nonpolar m-sapphire substrate using sputtering and high-temperature annealing. The evolution of crystalline structure and morphology was investigated by measurements and analysis, showing that annealing improved the crystalline quality. The influence of AlN-sapphire interface on crystalline quality and lattice parameters during annealing was found to be less significant with increasing film thickness. The annealing duration had no effect on crystalline quality but had a noticeable impact on morphology, indicating that crystalline reorganization occurs before morphology reset. The zig-zag morphology of the AlN template along the sapphire [0001] direction, resulting from annealing, could affect the subsequent device epitaxy process.
Article
Chemistry, Physical
Xu Li, Jianyun Zhao, Ting Liu, Yong Lu, Jicai Zhang
Summary: The research suggests that high-temperature nitridation is advantageous for the formation of semi-polar single oriented AlN films, with hole size playing a role in promoting the rapid coalescence of AlN micro-grains but expanding hole size starting to have a negative impact on grain coalescence as nitridation temperature further increases.
Article
Multidisciplinary Sciences
Dingding Ren, Chao Dong, Sadhvikas J. Addamane, David Burghoff
Summary: The longwave infrared (LWIR) region holds great potential for high-performance sensing and imaging. However, achieving precision sensors and broadband frequency combs in this region has been challenging. In this study, the authors demonstrate the fabrication of high-quality microresonators using native germanium, allowing for improved measurements and opening up possibilities for sensing and nonlinear photonics in the LWIR regime.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Dingding Ren, Chao Dong, Sadhvikas J. Addamane, David Burghoff
Summary: High-quality microresonators in the LWIR have been demonstrated using native germanium, paving the way for the development of novel sensing and nonlinear photonics in this regime.
NATURE COMMUNICATIONS
(2022)
Article
Optics
Victor Vassiliev, Michael Sumetsky
Summary: By experimenting, it is demonstrated that the side-coupling of coplanar bent optical fibres can induce high Q-factor whispering gallery mode optical microresonators that are fully mechanically reconfigurable. The dimensions and free spectral range of these microresonators can vary within a wide range. The new microresonators may have applications in various fields, such as cavity QED, microresonator optomechanics, frequency comb generation with tuneable repetition rate, tuneable lasing, and tuneable processing and delay of optical pulses.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Optics
Xi Wu, Tianren Fan, Ali A. Eftekhar, Amir H. Hosseinnia, Ali Adibi
Summary: This study demonstrates the first high-Q silicon carbide integrated photonic sensor based on slot-ring resonators on a SiCOI platform. By applying different concentrations of a sodium chloride solution, measured bulk sensitivities are achieved in the slot-ring resonator, proving its performance for biomolecular layer sensing, detecting cardiac biomarkers. The reported slot-ring resonators can be used for diverse sensing applications from visible to infrared wavelengths.
Article
Optics
Shuai Wan, Rui Niu, Jin-Lan Peng, Jin Li, Guang-Can Guo, Chang-Ling Zou, Chun-Hua Dong
Summary: In this work, Si3N4 microring resonators were fabricated for soliton microcomb generation. By developing a fabrication process with crack isolation trenches and annealing, high-quality Si3N4 films were deposited without cracks, resulting in a high intrinsic Q of 6 x 10(6) and low propagation loss of 0.058 dBm/cm. With these microrings, soliton microcombs were generated using 100 mW on-chip pump power, with an optical parametric oscillation threshold of only 13.4 mW. The Si3N4 integrated chip provides an ideal platform for nonlinear photonics and integrated photonics research and applications.
CHINESE OPTICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Jihong Kim
Summary: In this study, epitaxial AlN thin films were successfully grown on a Mo electrode/sapphire substrate at a low temperature, showing a specific in-plane relationship with sapphire. On the other hand, deposition of AlN on a Mo/SiO2/Si substrate resulted in poorly oriented films with a polycrystalline structure due to the presence of different low-crystalline phases in the Mo layer.
Review
Nanoscience & Nanotechnology
Nanxi Li, Chong Pei Ho, Shiyang Zhu, Yuan Hsing Fu, Yao Zhu, Lennon Yao Ting Lee
Summary: Aluminum nitride (AlN) is a CMOS-compatible material that overcomes the limitations of silicon, with a wide transparency window and significant nonlinear optical effects, suitable for various functional photonics devices.
Article
Engineering, Electrical & Electronic
Yujie Ai, Hongrui Lv, Yinglong Huang, Jiaheng He, Ye Wang, Jiwen Wu, Yun Zhang
Summary: In this study, a surface acoustic wave (SAW) resonator with high quality factors (Q) of 3526/10 205 at the resonant/antiresonant frequencies (f(r)/f(a)) was successfully fabricated on thick metal-organic chemical vapor deposition (MOCVD)-grown (0002) aluminum nitride (AlN) films (4 μm) on sapphire. The investigation on device parameters, including aspect ratio of length to width (L/W), number of interdigital transducers (IDTs), and IDT metal thickness, revealed that the high Q was achieved due to the large L/W value of 12 and the thick AlN film (4 μm). Furthermore, the resonator exhibited a high Q of 4027 at 250 °C and temperature coefficient of frequency (TCF) values of -46.52/-46.09 ppm/°C for f(r)/f(a) in the temperature range from -50 °C to 250 °C, showing promising potential for temperature sensor application.
IEEE SENSORS JOURNAL
(2023)
Article
Biotechnology & Applied Microbiology
Andrew E. S. Barentine, Yu Lin, Edward M. Courvan, Phylicia Kidd, Miao Liu, Leonhard Balduf, Timy Phan, Felix Rivera-Molina, Michael R. Grace, Zach Marin, Mark Lessard, Juliana Rios Chen, Siyuan Wang, Karla M. Neugebauer, Joerg Bewersdorf, David Baddeley
Summary: This study presents an integrated acquisition and analysis platform for single-molecule localization microscopy, which enables the imaging and analysis of 10,000 cells per day. The platform utilizes microscopy-specific data compression, distributed storage, and distributed analysis to increase throughput and allows for automated analysis initiation from the microscope. The platform also supports imaging of multiple cells in multi-well sample formats.
NATURE BIOTECHNOLOGY
(2023)
Article
Optics
Zixian Wei, Zhongxu Liu, Xin Liu, Lei Wang, Lai Wang, Changyuan Yu, H. Y. Fu
Summary: The study achieved a breakthrough in overcoming LED bandwidth limitations and implemented an artificial neural network equalizer for high-speed data transmission in VLC systems. With the use of signal modulation techniques, a data rate of 8.75 Gbps was achieved.
Article
Engineering, Electrical & Electronic
Shuhan Yang, Changzheng Sun, Bing Xiong, Jian Wang, Hao Zhibiao, Yanjun Han, Lai Wang, Hongtao Li, Jiadong Yu, Yi Luo, Yoshiaki Nakano
Summary: This study demonstrates the implementation of gain-coupled 4 x 56 Gb/s electroabsorption modulated laser (EML) arrays through the optimization of bonding-wire length, achieving modulation bandwidth over 40 GHz and low microwave reflection. Clear eye opening under 56 Gb/s nonreturn-to-zero (NRZ) modulation and transmission through 10 km single-mode fiber (SMF) have been successfully achieved.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2022)
Article
Physics, Applied
Jiadong Yu, Lai Wang, Jian Wang, Zhibiao Hao, Yi Luo, Changzheng Sun, Yanjun Han, Bing Xiong, Hongtao Li
Summary: Temperature-dependent photoluminescence (TDPL) is commonly used to evaluate the internal quantum efficiency (IQE) of light-emitting semiconductors. However, this study found that TDPL is not reliable for InGaN quantum well samples with high threading dislocation density (>10(10) cm(-2)). Power-dependent photoluminescence (PDPL) must be used to confirm the IQE at low temperature and calibrate the TDPL values. A phenomenological model is proposed to explain the relationship between IQE and threading dislocation density.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Review
Engineering, Electrical & Electronic
Luming Yu, Lai Wang, Zhibiao Hao, Yi Luo, Changzheng Sun, Bing Xiong, Yanjun Han, Jian Wang, Hongtao Li
Summary: This review discusses the developments of high-speed micro-LEDs in visible light communication (VLC). It highlights the advantages, problems, and challenges of micro-LEDs in VLC and reviews the achievements in bandwidth improvement while also providing future research directions.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Enfei Chao, Bing Xiong, Changzheng Sun, Zhibiao Hao, Jian Wang, Lai Wang, Yanjun Han, Hongtao Li, Jiadong Yu, Yi Luo
Summary: Novel back-illuminated modified uni-traveling-carrier photodiodes (MUTC-PDs) demonstrate wide bandwidth and high output power performance in the D-band (110-170 GHz) regime. The use of different coplanar waveguide (CPW) designs results in PDs with minimal output power roll-off and high saturation performance, with measured frequency responses in excellent agreement with simulations. Proper CPW electrode design allows for maintaining high performance over a broadband frequency range of 130-170 GHz.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Xuecheng Liu, Hao Liu, Bing Xiong, Changzheng Sun, Zhibiao Hao, Lai Wang, Jian Wang, Yanjun Han, Hongtao Li, Yi Luo
Summary: The study demonstrates a meandered X-cut TFLN Mach-Zehnder modulator with specially designed capacitively-loaded traveling-wave electrodes (CL-TWEs). Ultra-low V-pi of 1.08 V is achieved on an 8-mm-long modulator containing three segments of 7-mm-long modulation sections, along with a 3-dB electro-optic bandwidth around 43 GHz.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2022)
Article
Physics, Applied
Jiadong Yu, Zixuan Zhang, Yi Luo, Jian Wang, Lai Wang, Xiang Li, Zhibiao Hao, Changzheng Sun, Yanjun Han, Bing Xiong, Hongtao Li
Summary: This study reports the fabrication of high-quality gallium nitride (GaN) films using the ICP-MOCVD method at a low temperature. The GaN films were then used to produce thin-film transistors and photodetectors. The results show that these films exhibit excellent performance, demonstrating their potential for electronic device fabrication.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Multidisciplinary Sciences
Jiyuan Zheng, Xingjun Xue, Cheng Ji, Yuan Yuan, Keye Sun, Daniel Rosenmann, Lai Wang, Jiamin Wu, Joe C. Campbell, Supratik Guha
Summary: By replacing a fixed quenching resistor with a bias-dependent adaptive resistive switch, the recovery speed and frequency response of single-photon avalanche diodes can be significantly improved.
NATURE COMMUNICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Xuecheng Liu, Bing Xiong, Changzheng Sun, Zhibiao Hao, Lai Wang, Jian Wang, Yanjun Han, Hongtao Li, Yi Luo
Summary: This letter presents a velocity-matched TFLN modulator based on low-loss capacitively-loaded traveling-wave electrodes (CL-TWEs) with an on-chip terminal resistor. The effect of termination resistance on the E-O frequency response is analyzed theoretically and confirmed experimentally. The results show that an ultra-flat E-O response can be achieved with a termination resistance slightly lower than the characteristic impedance of the CL-TWEs.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Yunwei Ma, Ming Xiao, Zhonghao Du, Lei Wang, Eric Carlson, Louis Guido, Han Wang, Lai Wang, Yi Luo, Yuhao Zhang
Summary: This study addresses the activation of buried p-GaN layers in emerging GaN devices. It is found that the breakdown E-field and leakage current of sidewall-activated p-GaN layer are determined by the edge area with the highest activation efficiency. The leakage mechanism follows the trap-assisted tunneling model. These findings provide critical information for the design and processing of advanced GaN devices.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Physics, Applied
Boyang Lu, Zhibiao Hao, Yi Luo, Changzheng Sun, Yanjun Han, Bing Xiong, Jian Wang, Hongtao Li, Lai Wang
Summary: In this study, a simplified trap-assisted tunneling model is established to explain the experimental results by considering the energy distribution on trap states. The nonuniform distribution of diffused p-type dopants is identified as the cause of abnormal photocurrent experimental results.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Ruo-Chen Zhao, Zhi-Biao Hao, Lai Wang, Jian Wang, Bing Xiong, Chang-Zheng Sun, Yan-Jun Han, Hong-Tao Li, Ning Zhuo, Feng-Qi Liu, Yi Luo
Summary: A novel InGaAs/AlInAs quantum cascade detector (QCD) with localized electric field is proposed, which achieves 40% higher extraction efficiency of photon-induced electrons compared to conventional QCDs. The localized electric field, induced by modulation doping, greatly influences the electron transport by extending the regulation of electronic states in quantum wells. The extraction efficiency is enhanced by enlarging the transition matrix element related to the extraction process. The proposed mid-IR QCD exhibits a peak responsivity of 156.9 mA/W and a Johnson noise limited detectivity of 1.9 x 1011 Jones at 80K.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2023)
Article
Optics
Yuxin Tian, Bing Xiong, Changzheng Sun, Zhibiao Hao, Jian Wang, Lai Wang, Yanjun Han, Hongtao Li, Lin Gan, Yi Luo
Summary: Novel back-illuminated modified uni-traveling-carrier photodiodes (MUTC-PDs) with wide bandwidth and high saturation power are demonstrated. The effect of cliff layer doping on the electric field distribution is investigated to achieve fast carrier transport. MUTC-PDs with miniaturized device diameter and low contact resistance are fabricated to improve the RC-limited bandwidth. Meanwhile, inductive peaking is implemented to further extend the bandwidth. PDs with 3-pm and 3.6-pm-diameter exhibit a ultrawide bandwidth of 230 GHz and 200 GHz, together with -4.94 dBm and -2.14 dBm saturation power at 220 GHz and 200 GHz, respectively.
Letter
Optics
Zhaoqin He, Changzheng Sun, Bing Xiong, Jian Wang, Zhibiao Hao, Lai Wang, Yanjun Han, Hongtao Li, Lin Gan, Yi Luo
Summary: The dispersion characteristics of a microresonator are crucial for nonlinear optics applications. This study presents a simple and convenient method for measuring the dispersion profile of high-quality-factor GaN microrings using a single-mode fiber ring. The proposed method accurately determines the dispersion parameters by polynomial fitting based on the microresonator dispersion profile, which is further verified with frequency comb-based spectroscopy. The obtained dispersion profiles from both methods agree well with simulations.
Article
Optics
Haoqiang Wang, Yi Luo, Hongtao Li, Zihan Zang, Yunpeng Xu, Yanjun Han, Changzheng Sun, Zhibiao Hao, Lai Wang, Bing Xiong, Jian Wang, Lin Gan
Summary: In this paper, an extended ray-mapping method is proposed that incorporates differentiable ray-tracing into the design pipeline, allowing for accurate surface construction and efficient shape correction. The method involves two optimization stages and has successfully designed non-paraxial and off-axis illumination lenses in a short time. Simulation results demonstrate the effectiveness and robustness of the approach.
