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Microwave and Particle Beam Sources and Directed Energy Concepts 1989

作者： Gilgenbach, R.M. Wang, J.G. Choi, J.J. Outten, C.A. Spencer, T. Intense Energy Beam Interaction Laboratory Department of Nuclear Engineering Cooley Building North Campus University of Michigan Ann ArborMI48109-2104 United States

Experiments are underway to investigate the generation of MW to GW microwave power levels utilizing intense (1-10 kA), relativistic (0.4-1 MV), electron beams with pulselengths from 0.4 to 1 µs. Significant research issues concern the effects of beam voltage fluctuations and space charge on long-pulse microwave emission power and frequency stability. Two prototype masers have been developed utilizing a moderate energy pulseline generator with peak parameters: 0.4 MV, 1.2 kA, and 0.4 µs. Prototype I utilized a nonadiabatic step in the diode magnetic field to impart a large a (vL/v11˜1-2) to a relatively low transported current of 30-60A. With a uniform waveguide resonator this maser generated peak microwave power levels of 0.6 MW and pulselengths of 0.3 µs over 85% voltage droop. The emission frequency was close to the relativistic cyclotron frequency. The Prototype ii maser employed an improved magnetic field profile which transported 500-1000 A of beam current, but at a lower value of a (0.2-0.3). A series of permanent magnet wiggler/kickers were used in preliminary tests. Power levels were achieved in the range of 2 MW in the X-band and at MW levels in the K-band. These emission frequencies apparently correspond to the CRM forward-wave and backward-wave interaction with the TE11n cavity modes. By lowering the magnetic field below a critical value the microwave emission was cut off. design studies have been performed for a long-pulse MW-GW cyclotron maser on the MELBA accelerator with parameters: 0.8-1 MV, 1-10 kA, and 1-1.5 µs. © 1989 SPIE. All rights reserved.

关键词： Masers

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Analytical model for thermal instability of low voltage power MOS and SOA in pulse operation

Analytical model for thermal instability of low voltage powe...

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International Symposium on Power Semiconductor Devices and Ics (ISPSD)

作者： P. Spirito G. Breglio V. d'Alessandro N. Rinaldi Dept. of Electronics Engineering Università di Napoli “Federico II” Napoli Italy

Thermal instability presented by some high current power MOS has been shown to limit significantly the SOA capability. In this paper, we present a new analytical model to explain this type of instability in transient operation, based on an analytical formulation for both the positive temperature coefficient of the drain current and for the thermal resistance. The model is capable of predicting the onset of thermal instability for a given device structure and layout, and can be used both to define the allowed SOA of the device and as a design guide to design more rugged devices.

关键词： Analytical models Low voltage Temperature distribution Semiconductor optical amplifiers Transient analysis Thermal resistance MOS devices Spatial resolution Power engineering and energy Thermal engineering

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飞秒激光加工微纳光学器件

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光电工程 2023年第3期50卷 74-99页

作者：董彬张娟王达伟张亦元张乐然李瑞辛晨刘顺利张子航吴昊蒋绍军朱苏皖刘炳瑞吴东中国科学技术大学精密机械与精密仪器系中国科学院材料力学行为与设计重点实验室安徽省高等学校精密科学仪器重点实验室安徽合肥230026 中国科学技术大学第一附属医院生命科学与医学部安徽合肥230001

光学器件正在向着小型化、集成化以及柔性可变形等方向发展,基于集成微纳光学器件的光学系统以其较低的功耗、快速的响应时间以及高信息容量等优势脱颖而出。然而目前的高精度微纳加工手段如聚焦离子束(focused ion beam,FIB)刻蚀、半... 详细信息

光学器件正在向着小型化、集成化以及柔性可变形等方向发展,基于集成微纳光学器件的光学系统以其较低的功耗、快速的响应时间以及高信息容量等优势脱颖而出。然而目前的高精度微纳加工手段如聚焦离子束(focused ion beam,FIB)刻蚀、半导体光刻等工艺复杂,且缺乏灵活性。飞秒激光作为一种非接触、高精度、高脉冲强度的“冷”加工工具在微纳加工方面受到格外青睐。本文首先阐述了飞秒激光加工微纳光学器件的背景及相关机理,然后讨论了提高飞秒激光加工分辨率的各种方法,接着综述了基于飞秒激光的多种先进加工手段,其后总结了近年来飞秒激光加工微透镜、光栅、光波导以及光子晶体方面的代表性研究进展。最后,本文概括了飞秒激光加工微纳光学器件研究领域所面临的挑战以及未来发展方向。

关键词：飞秒激光高精度微纳结构光学器件

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Graphene-Coated Microring Resonator (MRR)-based Gas Sensor using Novel Intensity-Level Detection for low-cost, rapid, and label-free Sensing: Preliminary Simulated Results

Graphene-Coated Microring Resonator (MRR)-based Gas Sensor u...

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URSI Atlantic Radio Science Conference (URSI AT-RASC)

作者： Kent C. Soria Benjamin B. Dingel Jezlor Villarde Ramon C. Lapina Cindy Lisa Esporlas Luther Villacruz Kryss Urbano Francesca Palabrica Clint Dominic Bennett Department of Physics School of Science and Engineering Ateneo de Manila University Quezon City Philippines Nasfine Photonics Inc. Painted Post NY USA

ISBN: (数字)9789463968102

ISBN: (纸本)9798350360257

Almost all current microring resonator (MRR) based sensors rely on a wavelength shift detection scheme. This involves (i) expensive tunable lasers as an input source and (ii) optical spectrum analyzers as a detector, which leads to overall bulky configuration, high cost, and complex arrangement. Here, we propose a low-cost, tapered waveguide MRR-based gas sensor that uses a simple intensity-level detection method. It employs (1) a low-cost laser source and (2) a photodetector. The MRR is coated with graphene to detect the specific target element. This design can significantly reduce the overall cost and complexity of the sensing system.

关键词： Costs Graphene optical device fabrication optical resonators Waveguide lasers Photodetectors Safety

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显微集成术中光学相干断层血流造影术

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中国激光 2022年第15期49卷 119-126页

作者：张子艺俞晨阳乔依琳沈丽君程丹李鹏浙江大学光电科学与工程学院浙江杭州310027 浙江大学嘉兴研究院智能光电创新中心浙江嘉兴324000 温州医科大学附属眼视光医院杭州院区眼底病专科浙江杭州310020

提出一种集成手术显微镜的术中光学相干血流造影系统(iOCTA)来实现术中眼底视网膜血流灌注的动态监测。通过光学相干断层扫描血管造影(OCTA)系统的光路与商用手术显微镜的助手镜的成像光路耦合,实现显微镜-OCTA的系统集成,这种简捷的耦... 详细信息

提出一种集成手术显微镜的术中光学相干血流造影系统(iOCTA)来实现术中眼底视网膜血流灌注的动态监测。通过光学相干断层扫描血管造影(OCTA)系统的光路与商用手术显微镜的助手镜的成像光路耦合,实现显微镜-OCTA的系统集成,这种简捷的耦合方式便于现有手术显微镜的功能升级。采用基于逆信噪比和去相关的光学相干血流运动造影(ID-OCTA)算法,实现高信噪比的眼底微血管成像。利用该系统实现了活体兔眼的术中眼底血流灌注成像,揭示了血流灌注随眼内压的时空动态演变过程,发现急性高眼内压(60 mmHg;1 mmHg=133.32 Pa)将导致血流灌注密度值在短时间内降低至基线值的20%以下。所研制的iOCTA系统有望实现眼科手术中眼底血流灌注的实时监测,有助于外科医生客观评价手术过程和预测术后效果。

关键词：医用光学生物医学成像光学相干层析成像光学相干血流造影术中成像

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Study on Influence of Lightning Arrester Configuration on VFTO in 420kV GIS Substation Overvoltage in 420kv GIS Substation transformation project 2

Study on Influence of Lightning Arrester Configuration on VF...

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2nd International Conference on Energy, Power, and Electrical Technology, ICEPET 2023

作者： Feng, Ruming Che, Chuanqiang Zhai, Zhikai Xu, Qian Zhao, Lei Bai, Jie Liu, Taowei Kou, Zheng Chong, Jiali Co. Ltd. Inner Mongolia Power Research Institute Branch Inner Mongolia Huhhot010000 China Inner Mongolia Enterprise Key Laboratory of High Voltage and Insulation Technology Inner Mongolia Huhhot010000 China Tongliao Power Supply Company State Grid East lnner Mongolia Electric Power Company Inner Mongolia Tongliao028000 China Co. Ltd. Hohhot Power Supply Company Inner Mongolia Huhhot010000 China

ISBN: (纸本)9781510668270

Lightning impulse overvoltage is the main factor to determine the insulation level of substation, and the insulation coordination between the insulation level of the protected electrical equipment and the arrester of the protection device is the most basic and important insulation coordination in the power system. In this paper, the working principle, characteristics and lightning current simulation of zinc oxide arrester are described. Then, taking a 420kV gis substation as an object, an electromagnetic transient simulation platform is built by using electromagnetic transient program (EMTP-ATP), which is used to simulate 420kV When the 400 kV side of GIS Substation is struck out of the line tower by lightning, the insulator flashover occurs, and then it invades the substation along the transmission line to generate Lightning Overvoltage on the equipment. Considering the operation mode of single line single bus single transformer with the most serious overvoltage, the overvoltage waveform of the voltage transformer at the outlet end and the main transformer port of the 420kV GIS Substation is obtained under the given arrester configuration scheme. Through calculation and analysis, the design meets the requirements of specifications and engineering practice. © 2023 SPIE. All rights reserved.

关键词： ii-VI semiconductors

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Overcoming High Frequency Limitations of current-Mode Control Using a Control Conditioning Approach — Part ii: Implementation and Hardware

arXiv

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arXiv 2022年

作者： Cui, Xiaofan Avestruz, Al-Thaddeus The Department of Electrical and Computer Engineering University of Michigan Ann ArborMI48109 United States

This article is the second part of a paper series about interference in extremum (i.e., peak or valley) current-mode control, which applies to both fixed and variable switching frequency power converters. Specifically, this part presents three control conditioning methods that mitigate the adverse effect of interference. These methods are new ways to use: (i) slope compensation;(ii) low-pass filtering;and (iii) the phenomenon of comparator-overdrive-delay, for control conditioning. The stability criterion, closed-loop dynamics, and transient performance are derived with mathematical rigor for each method. The design tradeoffs are illustrated, discussed, and compared. The effectiveness of all three methods are demonstrated and validated in hardware using a power converter operating at multi-MHz switching frequencies. Copyright © 2022, The Authors. All rights reserved.

关键词： Comparators (optical)

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current density of carriers and emission rate in zinc selenide LED

Current density of carriers and emission rate in zinc seleni...

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International Conference on Electronic design (ICED)

作者： U.K. Sahbudin M.H.A. Wahid P. Poopalan N.A.M. Ahmad Hambali M.M. Shahimin S.N. Ariffin N.N.A. Saidi M.A.M. Azidin Semiconductor Photonics & Integrated Lightwave Systems (SPILS) School of Microelectronic Engineering Universiti Malaysia Perlis Perlis Malaysia Semiconductor Photonics & Integrated Lightwave Systems (SPILS) School of Microelectronic Engineering Universiti Malaysia Perlis Arau Perlis MY Faculty of Engineering National Defence University of Malaysia (UPNM) Kuala Lumpur

ISBN: (纸本)9781509021611

This work is based on the development of LED using a circular chip of ZnSe. Proper analyses of the proposed LED are performed by adding optical transition and nonradiative recombination processes. The voltage applied to the ZnSe LED ranges from 0 V to 3.5 V. The current-voltage characteristic and the flow of current density are obtained. At 2.5 V, the carriers move towards n-contact hence reduces the internal quantum efficiency. The carriers are observed to drift in opposite direction of the electric field until recorded voltage of 3.5 V where both carriers in line with the electric field. The emission at low voltage in p-layer is localized and caused the efficiency to reduce considerably.

关键词： Light emitting diodes Charge carrier processes ii-VI semiconductor materials Zinc compounds current density Radiative recombination

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Roles of Bioelectronics for Quality of Life

Roles of Bioelectronics for Quality of Life

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European Conference on Solid-State Circuits (ESSCIRC)

作者： H. Schmidt A. Shakouri M. Isaacson S. M. Kang Baskin School of Engineering University of California Santa Cruz Santa Cruz CA USA

Bioelectronics is an important technology in enhancing the quality of life, especially for those who are suffering from physiological difficulties. Novel biomimetic microelectronic systems will enable treatment of some of presently incurable human handicaps such as hearing loss, blindness (retinal prosthesis), paralysis (neuron-muscular prosthesis), and memory loss (cortical prosthesis). With advancement of bionanotechnology and quantitative medical research, the potential application of biomimetic systems is highly promising. In this paper we review the current status of biomimetic microelectronic systems and challenging issues in basic interface between electrodes and neuronal network, laboratory on a chip (LoC), and generation of power for implantable devices. For laboratory-on-a-chip (LoC), we examine a new way of detecting and sensing molecules on a chip with single molecule/particle sensitivity by fusing integrated optics with microfluidics, based on integrated hollow-core antiresonant reflecting optical waveguides (ARROW) waveguides. With multilayer dielectric confinement, the light is guided through hollow channels with cross sections of a few microns squared. We have demonstrated efficient light guiding in liquid-core ARROWs, single-molecule fluorescence sensitivity in fully planar beam geometry, surface-enhanced Raman scattering, fluorescence from live ribosomes in buffer solution, and electrical fluorescence control by applying a voltage between fluidic reservoirs connected to the waveguide channels. For electrical power sourcing of implantable biomimetic devices and systems, we illustrate the potential of the diffusion potential differences established between two half-cells of electrolyte solutions of different concentrations to generate directly an electric current. This concentration cell operates solely on a salt concentration gradient. The future advancement of biomimetic systems design will critically depend on computer aids as in VLSI developments

关键词： Biomimetics Prosthetics optical waveguides Fluorescence Laboratories Lab-on-a-chip Power generation Integrated optics optical buffering optical waveguide components

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High power, high efficiency interband cascade lasers

High power, high efficiency interband cascade lasers

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IEEE Photonics Conference (IPC)

作者： J.L. Bradshaw J.D. Bruno J.T. Pham D.E. Wortman R.Q. Yang U.S. Army Research Laboratory MD USA

Interband cascade (IC) laser designs can circumvent the fast phonon scattering loss in intersubband QC lasers and suppress Auger recombination through band-structure engineering resulting in a low threshold current density. These properties make mid-IR IC lasers based on InAs-GaInSb type-ii QWs promising for delivering high output powers and relatively high operating temperatures.

关键词： Quantum cascade lasers optical design Phonons Scattering design engineering Power engineering and energy Threshold current Power lasers Power generation Temperature

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