一种高增益Cuk变换器

为了提高传统Cuk变换器的电压增益和变换器工作效率、同时减小电流纹波和变换器的体积重量。提出一种适用于光伏发电系统的高增益Cuk变换器。利用带有自举电容的开关电感单元替代传统Cuk变换器中的输入电感,并对开关电感单元与输出电感进行了磁集成。分析了变换器的工作模态,推导得到了变换器电压增益表达式;分析了二极管与开关管电压应力的大小,给出了电感耦合度的设计准则。给出了高增益Cuk变换器集成磁件设计方案,并给出了设计方法。与传统Cuk变换器相比,高增益Cuk变换器的电压增益提高了2倍。仿真与样机实验结果验证了理论分析的正确性,表明提出的高增益Cuk变换器具有优良的综合性能。     

Electromagnetic torsion mirrors for self-aligned fiber-opticcrossconnectors by silicon micromachining

We report a micromechanical fiber-optic switch (1 cm×1 cm×1 mm) based on an electromagnetically operated torsion mirror which is suitable for self-latching operation. The switch is fabricated by silicon micromachining technology, and self-alignment technique is employed to align optical fibers to the mirror. A small mirror of gold finished FeNiCo/polysilicon (150 μm×500 μm) is supported by two beams, and rotated around the axis in the magnetic field induced by an electromagnet. An incident light is redirected by the mirror in a free-space smaller than 1 mm³. Multimode fibers are used for optical coupling of small loss (-2.5 dB for reflection and -0.83 dB for transmission) at a wavelength 1.55 μm. Typical switching time is 10-25 ms, and switching contrast is larger than 45 dB. Magnetic torque and optical coupling are theoretically investigated     

Optical properties effects upon the collection efficiency of optical fibers in different probe configurations

When optical fibers are used for delivery and collection of light, two major factors affect the measurement of collected light: 1) light transport in the medium from the source to the detection fiber and 2) light coupling to the optical fiber (which depends on the angular distribution of photons entering the fiber). This paper studies the latter factor, describing how the efficiency of the coupling depends on the optical properties of the sample. The coupling dependence on optical properties is verified by comparing experimental data to a simple diffusion model and to a Monte Carlo (MC)-corrected diffusion model. Mean square errors were 7.9% and 1.4% between experiments and the diffusion, and experiments and the MC-corrected models, respectively. The efficiency of coupling was shown to be highly dependent on the numerical aperture (NA) of the optical fiber. However, for lower scattering, such as in soft tissues, the efficiency of coupling could vary two- and threefold from that predicted by fiber NA. The collection efficiency can be used as a practical guide for choosing optical fiber-based systems for biomedical applications.     

Unidirectional, Efficiency-Controlled Coupling from Microcavity Using Reflection Feedback

We propose a microcavity-to-waveguide side coupling system with a reflector at one end of the waveguide for the feedback. Using this system, one can get a unidirectional output from a microcavity-based light emitter, where the output coupling efficiency and the cavity loss can be enhanced or suppressed through tuning optical phase of the feedback. Theoretical calculations are confirmed by finite-difference time domain (FDTD) simulation of the coupling between a photonic crystal cavity and a microfiber with a perfect mirror attached. Unidirectional coupling from the photonic crystal cavity to the fiber with efficiency of 90% is demonstrated in the simulation     

Self-aligned packaging of an 8×8 InGaAsP-InP space switch

By using an efficient and alignment tolerant fiber-chip coupling technology we can realize semiconductor space switches with a new and highly promising modular architecture. We present a completely packaged 8×8 matrix switch based on InGaAsP-InP intended for routing applications around wavelength 1.55 μm. The matrix is composed of sixteen 1×8 InGaAsP-InP switches that are optically interconnected by a shuffle comprising 64 single-mode fibers (SMFs). All the fiber ports of the InGaAsP-InP chips are provided with monolithically integrated optical spot-size transformers (MOSTs) that allow simple yet highly efficient self-aligned multifiber coupling. The 8×8 matrix shows a fiber-matrix-fiber insertion losses of 20 dB and a crosstalk suppressions of 28 dB. An extension of the matrix architecture to a 64×64 switch seems straightforward     

An Optical Parametric Amplified Fiber Switch for Optical Signal Processing and Regeneration

An optical parametric amplified (OPA) fiber switch is described in this paper. This device switches input signals without shifting the wavelength by changing the polarization state of the signal using optical parametric amplification. The OPA fiber switch features ultra-broadband, highly efficient switching with a high contrast ratio. We experimentally test the prototype of the OPA fiber switch, which uses a highly nonlinear fiber. Optical demultiplexing of 160 Gb/s differential phase-shift keying (DPSK) signals is demonstrated in the whole C-band and shows that it provides almost penalty-free optical detection. The application of amplitude noise suppression with the OPA fiber switch by using parametric gain saturation is then proposed and demonstrated for a 160 Gb/s DPSK signal. When it is set to an amplitude-limiting condition, the OPA fiber switch successfully increases the optical signal-to-noise ratio by 4 dB and effectively suppresses the phase deterioration in 160 Gb/s DPSK transmission by increasing the system margin by more than 5 dB.     

A rotary electrostatic micromotor 1×8 optical switch

This paper describes a 1×8 rotary electrostatic micromotor optical switch fabricated using high-aspect-ratio micromachining technology to produce silicon or nickel components which are subsequently assembled to form a switch. The switch consists of a salient-pole micromotor with 1-mm-diameter 200-μm-thick rotor that supports up to a 500-μm-tall, 900-μm-wide mirror. Typical switches were actuated at 50 V, operated for extended periods in room air, and found to have a rapid rotation with an average optical switching time between two neighboring fiber ports of 18 ms. Optical testing was performed at wavelength of 1310 nm in single- and multimode, and at 850 nm in multimode. The optical beam was propagated in free space with minimal divergence through the use of externally mounted collimating gradient-index lenses. With an aluminum coating, the mirror and external optics exhibited an input to output coupling loss as low as 0.96 dB in multimode and 2.32 dB in single-mode. Interchannel crosstalk was less than -45 dB     

High-Voltage CMOS Controller for Microfluidics

A high-voltage microfluidic controller designed using DALSA Semiconductor's 0.8-$mu $m low-voltage/high-voltage complementary metal–oxide semiconductor/double diffused metal– oxide semiconductor process is presented. The chip's four high- voltage output drivers can switch 300 V, and the dc–dc boost converter can generate up to 68 V using external passive components. This integrated circuit represents an advancement in microfluidic technology when used in conjunction with a charge coupling device (CCD)-based optical system and a glass microfluidic channel, enabling a portable and cost-efficient platform for genetic analysis.      

O/E Integration of Polymer Waveguide Devices by Using Replication Technology

The simple optoelectronic integration of polymer-based optical waveguide devices and the development of the realization processes have been critical issues for cost-effective, high-volume manufacturing of a next-generation optoelectronic integrated circuit (OEIC). We demonstrated the replication technology as a means of implementing the polymer microoptoelectromechanical system (MOEMS)-based packaging structure providing the optical/electrical (O/E) integration of the functional polymer waveguide device. To achieve this, a micromechanical packaging structure consisting of an electric-circuit-embedded polymer optical bench and planar-lightwave-circuit (PLC)-type waveguide chip with alignment microstructure was designed, and the realization process incorporating the UV imprint technique was investigated. To improve optical coupling efficiency, the electric circuit was embedded under the optical bench and the contact pads were opened at the bottom of the alignment pits. In addition, a conductive adhesive-fill space was created at the alignment pits to accommodate the surplus conductive adhesive. Efficient fiber-chip coupling and good electrical contact of upside-down mounted single-mode waveguide chip was accomplished by the simple joining of the electric-circuit patterned micropedestals on the waveguide chip and the alignment pits on the bench. A coupling loss of 0.9 dB per coupling face was measured with a single-mode fiber at a wavelength of 1.5 mum. It was concluded that the replication technology has versatile application capabilities in manufacturing next generation optical interconnect systems     

数控有源箝位正激变换器的分析与设计

主要阐述了基于单片机控制下的改进型有源箝位正激变换器设计。实现宽范围电压输入、宽范围电压输出、输出电流可调等功能;具有过压保护、过流保护功能;能够较好地实现主开关管、箝位开关管的零电压开启,大大降低了开关损耗;采用同步整流技术和软开关技术进一步提高系统转换效率;处理器能够根据负载变化自动调整工作模式,即轻载模式、重载模式、待机模式。采用高速光耦合器隔离驱动方式,使得输出电压信号、电流信号直接反馈至PWM控制器,提高了闭环控制带宽,并且具有线性反馈等优点;处理器可根据输出电压或电流参数,并行调整PWM工作频率、占空比,实现PWM&PFM综合控制。经过实际电路制作验证了方案的可行性,说明数字电路结合有源箝位正激变换器具有更多优点。     

Photoconductive switch design for microwave applications

A procedure for choosing the dimensions of a photoconductive semiconductor switch (PCSS) for operation at microwave switching frequencies, and particularly at 10.0 GHZ, is described. The critical dimension is the switch length (electrode separation), which must be small enough to force photoinduced charge removal during switch turn-off via sweep out rather than recombination. The switch depth in the direction of turn-on optical pulse absorption must be several optical absorption depths long to ensure absorption of all the incident light, which optimizes optical to electrical signal gain. The switch width is determined in conjunction with the peak intensity of the optical pulse because the switch width-optical intensity product, which represents optical power, determines the turn-on time, the on-state switch resistance and the turn-off delay time. Simulations show that a switch with a 0.5 μm length, 5.0 μm depth, and 20 μm width, illuminated with 1.0 W peak power optical pulses at 10 GHz, will have a 4.8 ps turn-on time, a 0.23 Ω on-state resistance, and a 46 ps turn-off time.     

Polymeric electrooptic 2×2 switch consisting of bifurcationoptical active waveguides and a Mach-Zehnder interferometer

We interpret the modified bifurcation optically active waveguide switch structure for a polymeric electrooptic (EO) 2×2 switch. PEI-DR1, UFC150, and Resole HM2 were used as the core EO material, the lower clad material, and the upper clad material, respectively. We present the optical and electrical properties on this material system for high-performance devices. We fabricate the electrically and optically packaged polymeric EO 2×2 switch for high-speed optical communications. At an operating voltage of 8.5 V, the crosstalk of the cross-arm is -18.1 dB, and that of the straight arm is -18.5 dB. The measured optical loss is 14 dB at λ=1.3 μm. The 6-dB attenuation in radio-frequency transmission corresponds to about 17 GHz     

一种基于模块化多电平变换器拓扑的柔性母联控制器

针对传统母联开关的各种缺陷,提出了一种基于模块化多电平变换器拓扑的柔性母联控制器。它可以连接不同电压等级的网络,实现潮流的优化调节、无功支撑及故障时交流系统之间的快速紧急支援和隔离故障。同时具备直流电压输出端口,可以用于交直流混合的配电网架中。对柔性母联控制器的工作模式进行了分析,设计了直流电压及潮流控制器。通过仿真及实验,验证了该控制器的性能。     

Mode coupling analysis for the design of refractive ion exchangeintegrated optical components

Refractive integrated optical planar components such as prisms and lenses, consist of alternating regions of high- and low-index planar waveguides. Boundary transmission losses depend on the coupling efficiency between the fundamental modes in the two regions. Hence, a choice of appropriate parameters to achieve maximum coupling efficiency is an important design criterion of these components. We propose the use of the Ritz-Galerkin (RG) procedure to characterize the modal fields in planar graded index waveguides for obtaining coupling efficiency and, hence, the optimal design features. The procedure is “exact” and simple analytical expressions have been obtained for coupling efficiency. Further, coupling to higher order modes can also be obtained to estimate the background noise in component design when parameters deviate from the optimum. To confirm the convergence, results have been compared with the exact numerical procedure based on the multilayer staircase approximation. Various variational procedures limited to the fundamental mode coupling efficiency calculations are also summarized in this paper along with a discussion on their accuracies     

Optical MEMS for photonic switching-compact and stable optical crossconnect switches for simple, fast, and flexible wavelength applications in recent photonic networks

We review the development trends and state-of-the-art technologies of large-port-count optical switches over the past decade. Practical implementation of optical switch fabrics is discussed in terms of optical switch architectures, optical configurations, port counts, switch elements, and so on. We describe compact and stable optical crossconnect three-dimensional microelectromechanical systems (3-D-MEMS) switches that are a key technology in recent photonic networks. To show how these enable simple, fast, and flexible wavelength applications in the photonic layer, we discuss the fast and stable MEMS switching by novel comb actuator and V-shaped torsion bar, compact optical configuration with roof-type mirror, stable switch housing with cubic structure, packaging techniques by tolerance expansion and simple procedures of the component assembly, MEMS mirror controller with fast and low power digital notch circuit, reliability by shock absorption, and field trials. In addition, we discuss the impact of these switches on system integration for recent metropolitan area networks and enterprise networks.     

光路自动切换保护技术的原理和应用设想

随着光通信技术在电力系统通信领域的大量应用,如何提高光传输网络的生存性已经成为至关重要的问题。文章首先对目前已有的几种提高通信可靠性的方法进行了比较,认为光路自动切换保护技术和SDH自愈保护技术结合,会大大提升光传输网络的生存性能;重点介绍了光路自动切换保护技术的原理,提出了两种实现自动光切换的方法,即根据光监测模块的告警和SDH网管告警,给出了一个应用设想的实例。     

电子开关自耦式交流稳压器

智能电子开关自耦交流稳压电源由两只自耦变压器组成两级调节方式。用双向晶闸管作为电子开关 ,双向晶闸管过零触发 ,因而输出的是完整的正弦波。再应用单片机和其他元件构成反馈控制网络 ,组成了交流稳压器。此设备具有响应速度快、输出的正弦波失真小、智能化程度高、抗干扰能力强、功率因数和效率高的特点。     

How to launch 1 W into single-mode fiber from a single 1.48-μmflared resonator

The operation of 1.48-μm flared resonators is thoroughly studied, both experimentally and theoretically: the accurate determination of threshold condition as a function of geometrical and material parameters, the study of emission spectra and astigmatism variations as a function of optical power level allow us to better understand the may these devices operate. The origin of modal distortion is then analyzed, and an original solution is proposed to increase the single-transverse-mode power at high injection level: it is shown that implanting the multiple-quantum-well active layer with protons efficiently enhances the filtering capability of the overall structure, and particularly that of the ridge waveguide, by bringing additional lateral absorption losses. The explanation of the filtering mechanism is successfully confirmed by simulations using the beam-propagation method. This technique finally allowed more than 1.3 W of continuous wave (CW) diffraction-limited power at 6 A. Low-modal-gain structures were then realized to reduce modal optical absorption in the implanted structures with a view to maintaining a high external efficiency and a reduced vertical divergence. Finally, a three-lens coupling system was designed and the effects of optical feedback minimized so as to obtain a very high coupling efficiency: with an improved laser design, 1.12 W of CW power were then coupled into single-mode fiber at 6.6 A, which represents 65% of the power emitted by the laser chip     

新型电感储能型电磁炮脉冲电源拓扑

提出了一种用于电磁发射的电感储能型电磁炮脉冲电源拓扑。该拓扑中两储能电感充电时串联,放电时并联,以实现电流倍增。与meatgrinder电路相比,该电路两储能电感之间不需要磁耦合,具有设计简单灵活、容易制造的特点。为避免电感储能断路时断路开关出现过电压问题,用电容作为能量转换器件可实现开关的零电压断路。对该脉冲电源系统的工作原理进行了理论分析,搭建了小型实验系统,验证了该电源拓扑的可行性。以轨道炮为负载,对电感、电容参数对系统性能的影响进行了仿真分析,结果表明多个电源模块的并联运行能明显提高系统能量转换效率。     

耦合电感二次型高增益Boost变换器

为解决二次型Boost变换器功率器件电压应力大以及耦合电感Boost变换器开关管电压尖峰高的问题,结合二次型Boost变换器和耦合电感Boost变换器的特点,提出一种耦合电感二次型高增益Boost变换器.该变换器能够吸收漏感能量,抑制开关管两端的电压尖峰,且能将漏感能量向负载传递,提高了变换器的工作效率;通过引入桥式倍...