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International Applied Computational Electromagnetics Society Symposium (ACES)

作者： Yiming Chen Wei Kang Guoxiao Cheng Wen Wu School of Electronic and Optical Engineering Nanjing University of Science and Technology Nanjing China

This paper introduces the design of a W-band voltage-controlled oscillator (vCO), which achieves very low phase noise and excellent figure of merit (FOM) at 1-MHz offset. The circuit is based on the Colpitts topology structure. The vCO is configured to operate at a fundamental frequency of 47 GHz and utilizes second harmonic extraction for output. Load pulling technique is employed at the output stage to achieve maximum output power. The vCO tank is set to the optimal capacitance ratio to ensure the lowest phase noise, which aligns closely with theoretical expectations. In addition, the combination of tail current noise optimization and resonant network filtering techniques is also used to improve phase noise. The circuit is designed using the 130-nm SiGe BiCMOS process. The designed area is only 0.06 mm 2 excluding pads. The vCO outputs a frequency range from 90 to 97 GHz. The phase noise at a 1-MHz offset is -101.5 dBc/Hz. With a voltage supply of 2.5v, the power consumption is 30 mW. The FoM at 1-MHz offset is -184.7 dBc/Hz.

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12.1 terabit/second data center interconnects using O-band coherent transmission with QD-MLL frequency combs

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NATURE COMMUNICATIONS 2024年第1期15卷 7741页

作者： Bernal, Santiago Dumont, Mario Berikaa, Essam St-Arnault, Charles Hu, Yixiang Castrejon, Ramon Gutierrez Li, Weijia Wei, Zixian Krueger, Benjamin Pittala, Fabio Bowers, John Plant, David v. McGill Univ Dept Elect & Comp Engn Montreal PQ H3A 0G4 Canada Univ Calif Santa Barbara Dept Elect & Comp Engn Santa Barbara CA 93106 USA Univ Nacl Autonoma Mexico Inst Engn Cd Uni Mexico City 04510 Mexico Keysight Technol Deutschland GmbH D-71034 Boblingen Germany

Most current Data Center Interconnects (DCI) use intensity modulation direct detection (IMDD) configurations due to their low complexity and cost. However, significant scaling challenges allow coherent solutions to become contenders in these short reach applications. We present an O-band coherent optical fiber transmission system based on Quantum Dot-Mode Locked Lasers (QD-MLLs) using two independent free-running comb lasers, one each for the carrier and the Local Oscillator (LO). Using a comb-to-comb configuration, we demonstrate a 10 km single mode fiber, O-band, coherent, heterodyne, 12.1 Tbps system operating at 0.47 Tbps/lambda using 26 lambda s. We used fewer comb lines (26 lambda s), faster symbol rate (56 GBaud) and higher constellation cardinality (32 QAM) relative to the highest capacity C-band systems reported to date. Through design, analysis, and experimentation, we quantify the optimum comb line spacing for this use case. We compare potential configurations for increasing data center interconnect capacities whilst reducing power consumption, complexity, and cost. The authors showcase a cutting edge12.1 Tbps coherent optical fiber transmission system using two Quantum-Dot Mode-Locked Lasers as both carrier and LO, which opens the way for a cost-effective solution to scaling intra-data center interconnects capacities.

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An integrated front-end vertical hall magnetic sensor fabricated in 0.18μm low-voltage CMOS technology

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Journal of Semiconductors 2022年第3期43卷 60-67页

作者： Zhengwu Shu Lei Jiang Xingxing Hu Yue Xu College of Electronic and Optical Engineering&College of Microelectronics Nanjing University of Posts and TelecommunicationsNanjing 210023China

An integrated front-end vertical CMOS Hall magnetic sensor is proposed for the in-plane magnetic field *** improve the magnetic sensitivity and to obtain low offset,a fully symmetric vertical Hall device(FSvHD)has been op-timized with a minimum size design.A new four-phase spinning current modulation associated with a correlated double sampling(CDS)demodulation technique has been further applied to compensate for the offset and also to provide a linear Hall output *** vertical Hall sensor chip has been manufactured in a 0.18μm low-voltage CMOS technology and it occu-pies an area of 1.54 *** experimental results show in the magnetic field range from-200 to 200 mT,the entire vertical Hall sensor performs with the linearity of 99.9%and the system magnetic sensitivity of 1.22 v/T and the residual offset of 60μ***,it consumes 4.5 mW at a 3.3 v supply *** proposed vertical Hall sensor is very suitable for the low-cost sys-tem-on-chip(SOC)implementation of 2D or 3D magnetic microsystems.

关键词： vertical Hall sensor dynamic offset cancellation 1/f noise residual offset

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Improve the performance of 2μm GaSb-based high-power lasers by reducing the thermal effect of series resistance 16

Improve the performance of 2μm GaSb-based high-power lasers...

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16th National Conference on Laser Technology and Optoelectronics

作者： Chen, Yihang Zhang, Yi Yang, Cheng'ao Shang, Jinming Wang, Tianfang Wang, Haiteng Xu, Yingqiang Zhang, Yu Niu, Zhichuan State Key Laboratory for Superlattices and Microstructures Institute of Semiconductors Chinese Academy of Sciences Beijing100083 China College of Materials Science and Opto-Electronic Technology University of Chinese Academy of Sciences Beijing100049 China CRRC YANGTZE CO. LTD China

ISBN: (数字)9781510646643

ISBN: (纸本)9781510646636

The resistivity of each layer constituting a 2μm GaSb-based laser is measured with van der Pauw method. The operation temperature of GaTe doping source is optimized for lower resistivity. The series resistance contribution of each layer is calculated. A new laser structure is designed, 65% of the optical field distributes in quantum wells and waveguide layers while the series resistance is reduced to 0.28ω.The laser with new design is fabricated, 0.89W continuous output power at room temperature can be achieved at a current of 3A with voltage of 1.40v. The slope efficiency of the emitter is 0.32W/A, and almost no slope efficiency is observed in the process of increasing current until 2.6A. © 2021 SPIE.

关键词： III-v semiconductors

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Single-Event Transient Tolerant optical Receiver Using Triple Modular Redundancy

Single-Event Transient Tolerant Optical Receiver Using Tripl...

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IEEE International Symposium on Circuits and Systems

作者： Sami Sattar Glenn Cowan Eecric nd Couer Engineering Concordi Universiy Monre CndEecric nd Couer Engineering Concordi Universiy Monre Cnd

ISBN: (数字)9781665484855

ISBN: (纸本)9781665484862

In this work, a single-event transient tolerant optical receiver using triple modular redundancy (TMR) is presented. The TMR method splits a conventional receiver into three identical receivers in parallel. Majority voting is performed at the outputs after the received signal has been sliced. The proposed SET tolerant optical receiver achieves a gain of 83 dB , a bandwidth of 7.2 GHz, and an input-referred noise current of 0.93 A_(rms). It operates at a supply voltage of 1 v and dissipates 33 mW of power. Analysis shows that adding TMR introduces a sensitivity penalty of only 0.8 dB.

关键词： Sensitivity Ionizing radiation Redundancy voltage optical receivers Adaptive optics optical design techniques

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Hayabusa2 pinpoint touchdown near the artificial crater on Ryugu: Trajectory design and guidance performance

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ADvANCES IN SPACE RESEARCH 2021年第8期68卷 3093-3140页

作者： Kikuchi, Shota Saiki, Takanao Takei, Yuto Terui, Fuyuto Ogawa, Naoko Mimasu, Yuya Ono, Go Yoshikawa, Kent Sawada, Hirotaka Takeuchi, Hiroshi Ikeda, Hitoshi Fujii, Atsushi Sugita, Seiji Morota, Tomokatsu Yamada, Manabu Honda, Rie Yokota, Yasuhiro Sakatani, Naoya Kameda, Shingo Kouyama, Toru Hirata, Naru Hirata, Naoyuki Shirai, Kei Kitazato, Kohei Nakazawa, Satoru Yoshikawa, Makoto Tanaka, Satoshi Wada, Koji Watanabe, Sei-ichiro Tsuda, Yuichi Japan Aerosp Explorat Agcy Inst Space & Astronaut Sci Sagamihara Kanagawa 2525210 Japan Japan Aerosp Explorat Agcy Res & Dev Directorate Sagamihara Kanagawa 2525210 Japan Univ Tokyo Tokyo 1130033 Japan Chiba Inst Technol Planetary Explorat Res Ctr Narashino Chiba 2750016 Japan Kochi Univ Kochi 7808520 Japan Rikkyo Univ Tokyo 1718501 Japan Natl Inst Adv Ind Sci & Technol Tokyo 1350064 Japan Univ Aizu Aizu Wakamatsu 9658580 Japan Kobe Univ Kobe Hyogo 6578501 Japan Nagoya Univ Nagoya Aichi 4648601 Japan

One of the major challenges in the Hayabusa2 sample-return mission was the second touchdown on the asteroid Ryugu, which was designed to collect subsurface materials near the artificial crater formed by a small carry-on impactor. Due to engineering and scientific requirements, a narrow area with a radius as small as 3.5 m was selected as the target landing site. To achieve pinpoint touchdown at the selected site, an artificial landmark called a target marker (TM) was used for optical navigation. The key to a successful touchdown was precise deployment of the TM in the microgravity environment of the asteroid. This study therefore investigates a viable trajectory for TM deployment, incorporating the uncertainty in the impact and rebound motions of the TM. Following the TM deployment operation, a detailed survey of the landing site around the TM settlement point is performed to assess the terrain conditions. To guarantee the observation quality and spacecraft safety, multi-impulse low-altitude trajectories are introduced in this paper, along with covariance analyses based on the high-fidelity polyhedral gravity model of Ryugu. Subsequently, a pinpoint touchdown trajectory that satisfies various engineering requirements, such as landing accuracy and velocity, is designed, taking advantage of optical TM tracking. The feasibility of the touchdown sequence is further validated by a Monte Carlo dispersion analysis. Consequently, Hayabusa2 successfully touched down within the target site on 11 July 2019. The current research also conducts a post-operation trajectory reconstruction based on the flight data to demonstrate the actual guidance performance in the TM deployment, landing site observations, and pinpoint touchdown. (C) 2021 COSPAR. Published by Elsevier B.v.

关键词： Asteroid landing Orbital motion Gravity field Payload deployment Autonomous navigation Trajectory reconstruction

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Spectral Bandwidth Recovery of optical Coherence Tomography Images using Deep Learning 12

Spectral Bandwidth Recovery of Optical Coherence Tomography ...

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12th International Symposium on Image and Signal Processing and Analysis (ISPA)

作者： Yu, Timothy T. Ma, Da Cole, Jayden Ju, Myeong Jin Beg, Mirza Faisal Sarunic, Marinko v. Simon Fraser Univ Sch Engn Sci Burnaby BC Canada Univ British Columbia Sch Biomed Engn Vancouver BC Canada

ISBN: (纸本)9781665426398

optical coherence tomography (OCT) is a non-invasive imaging modality utilized by ophthalmologists to acquire volumetric data to characterize the retina, the light-sensitive tissue at the back of the eye. OCT captures cross-sectional data and is used for the screening, monitoring, and treatment planning of retinal diseases. Technological developments to increase the speed of acquisition often results in systems with narrower spectral bandwidth, and hence a lower axial resolution. Traditionally, image-processing-based techniques have been utilized to reconstruct subsampled OCT data and more recently, deep-learning-based methods have been explored. In this study, we simulate reduced axial scan (A-scan) resolution by Gaussian windowing in the spectral domain and investigate the use of a learning-based approach for image feature reconstruction. Our experiment is limited by the size of our current dataset, and we leverage techniques like transfer learning from large natural image databases and image augmentation in our implementation. In anticipation of the reduced resolution that accompanies wide-field OCT systems, we attempt to reconstruct lost features using a pixel-to-pixel approach with an altered super-resolution GAN (SRGAN) architecture. Similar techniques have been used to upscale images of lower image size and resolution in medical images like radiographs. We build upon methods of super-resolution to explore methods of better aiding clinicians in their decision-making to improve patient outcomes.

关键词： Generative Adversarial Network Deep Neural Network Signal Reconstruction optical Coherence Tomography Retina

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Strong Kinetic-Inductance Kerr Nonlinearity with Titanium Nitride Nanowires

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Physical Review Applied 2022年第6期18卷 064088-064088页

作者： Chaitali Joshi Wenyuan Chen Henry G. LeDuc Peter K. Day Mohammad Mirhosseini Moore Laboratories of Electrical Engineering California Institute of Technology Pasadena California USA Institute of Quantum Information and Matter California Institute of Technology Pasadena California USA Jet Propulsion Laboratory Pasadena California USA

Thin films of disordered superconductors such as titanium nitride (TiN) exhibit large kinetic inductance (KI), high critical temperature, and large quality factors at the single-photon level. KI nonlinearity can be exploited as an alternative to Josephson junctions to create novel nonlinear quantum devices with the potential to operate at higher frequencies and at elevated temperatures. We study a means of magnifying KI nonlinearity by confining the current density of resonant electromagnetic modes in nanowires with a small volume v≃10−4μm3. Using this concept, we realize microwave-frequency Kerr cavities with a maximum Kerr shift per photon of K/2π=123.5±12 kHz and report a nonlinearity-to-linewidth ratio K/γ=21%. With improved design, our devices are expected to approach the regime of strong quantum nonlinearity in the millimeter-wave spectrum.

关键词： Kerr effect optical parametric oscillators & amplifiers optical sources & detectors Optoelectronics Quantum information with solid state qubits Superconducting quantum optics Nanowires RF, microwave, & terahertz sources

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Characteristics of silicon nanowire solar cells with a crescent nanohole

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OPTICS EXPRESS 2020年第21期28卷 31020-31033页

作者： Khaled, Awad Hameed, Mohamed Farhat O. Rahman, B. M. A. Grattan, K. T., v Obayya, S. S. A. Hussein, Mohamed Zewail City Sci & Technol Ctr Photon & Smart Mat Giza 12578 Egypt Zewail City Sci & Technol Nanotechnol & Nanoelect Engn Program Giza 12578 Egypt Mansoura Univ Fac Engn Math & Engn Phys Dept Mansoura 35516 Egypt City Univ London Dept Elect & Elect Engn London EC1V 0HB England Ain Shams Univ Fac Sci Phys Dept Cairo Egypt

In recent years, newly emerging photovoltaic (Pv) devices based on silicon nanowire solar cells (SiNW-SCs) have attracted considerable research attention. This is due to their efficient light-trapping capability and large carrier transportation and collection with compact size. However, there is a strong desire to find effective strategies to provide high and wideband optical absorption. In this paper, a modified circular nanowire (NW) with a nanocrescent hole is newly introduced and analyzed for solar cell applications. The crescent hole can strongly improve the light absorption through the NW due to the excitation of numbers of modes that can be coupled with the incident light. The material index, volume, and position of the nanohole are studied to significantly increase the optical absorption efficiency and hence the power conversion efficiency (PCE). The absorption performance can be further preserved by using a silicon substrate due to the coupling between the supported modes by the NW, and that of the substrate. The optical and electrical characteristics of the suggested design are investigated using finite difference time domain and finite element methods via Lumerical software packages. The reported asymmetric design offers higher optical and electrical efficiencies compared to the conventional NW counterpart. The proposed NW offers a short circuit current density (J(sc)) of 33.85 (34.35) mA/cm(2) and power conversion efficiency (PCE) of 16.78 (17.05) % with an enhancement of 16.3 (16.8) % and 17.3 (18.4) % for transverse magnetic (TM) and transverse electric (TE) polarizations, respectively, compared to the conventional cylindrical counterpart. (C) 2020 optical Society of America under the terms of the OSA Open Access Publishing Agreement

关键词： Electron beam lithography Finite difference time domain Finite element method optical absorption Silicon solar cells Solar cells

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Quantifying The Effects of Interface Defect Density on Charge Transport in CsPb0.625Zn0.375I2Br Solar Cells

Quantifying The Effects of Interface Defect Density on Charg...

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Renewable Energy and Sustainable E-Mobility Conference (RESEM), IEEE

作者： Navdeep Kaur Jaya Madan Rahul Pandey VLSI Centre of Excellence Chitkara University Institute of Engineering and Technology Chitkara University Punjab India

In current era of green energy, technology is shifting toward usability of solar energy. Among the popularly used semiconductor materials in photovoltaic devices, perovskite material has been investigated on large scale due to its excellent optical performance. The photovoltaic performance (Pv) of perovskite-based solar cells (PSC) has demonstrated exceptional performance in solar cell. Hybrid perovskite material possess high carrier life time, absorption co-efficient and diffusion length. In addition, it has feasibility to tune bandgaps to absorb different wavelengths. However, lead present in hybrid perovskite compounds is hazardous for environment. Also presence of organic cation is the main cause of thermal instability in hybrid perovskite. This study primarily aims to explore all inorganic halide perovskites (IHP) in photovoltaic cell. Due to outstanding optical performance and thermal stability of IHP materials, interest of researchers is shifting toward this material. The proposed design uses a low-lead IHP CsPb 0.625 Zn 0.375 I 2 Br, in the active layer of PSC structure. The device structure has simulated using simulator SCAPS-1D to verify the impact of interface defect density (IDD) at TiO2/ CsPb 0.625 Zn 0.375 I 2 Br and CsPb 0.625 Zn 0.375 I 2 Br / Spiro-MeOTAD interface. The IDD is varied in 7 logarithmic steps (10 12 cm -2 - 10 18 cm -2 ). Obtained results indicate the degradation in photovoltaic performance with increase in IDD. It has been noticed from the simulated results that power conversion efficiency (PCE) 22.96% to 16.58% with increase in IDD. The same impact is also observed on short circuit current density (JSC), open circuit voltage (vOC) and fill factor (FF), it decreases from 35.03 mA/cm 2 to 33.88 mA/cm 2 , 0.80 v to 0.61 v and 83.55 % to 79.92 % respectively.

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