1.54μm APD光电探测器组件的研制及应用

主要从长波长人眼安全测距方面讨论和研究了InGaAs雪崩光电二极管的前置放大器的电路原理和参数的设计以及光电探测器组件混合集成.着重从激光测距方面的应用探讨了由InGaAs雪崩光电二极管组成的激光接收器的应用电路的选择和设计.从测距使用的角度对InGaAs雪崩光电二极管的光电特性与偏置电压的关系进行了测试,从而了解该器件与硅雪崩二极管的光电性能的差异,从而为更好的应用InGaAs雪崩光电二极管提供参考和依据.研制的InGaAs雪崩光电二极管探测器组件及接收器在激光测距机中进行了测距应用,在激光能量为7毫焦耳测距集中进行测距,初步达到了要求.     

雪崩光电二极管在激光测距机中的应用

本文根据雪崩光电二极管的噪声特性．提出了按照噪声分配原则来确定雪崩光电二极管最佳工作点的方法。对放大器，接收光路设计和雪崩管的偏压电源等问题均进行了讨论。实验表明应用APD-1型雪崩光电二扳管，使激光测距系统的测程比用pin硅光电二极管时增加一倍以上，接收灵敏度提高27～15倍。     

光纤传感系统中APD增益温漂的动态补偿研究

为实现对雪崩光电二极管(APD)增益温漂的动态偏压补偿, 设计了高精度的ADC和DAC电路系统,对APD可以达到毫伏级的偏压控制精度和0.2 ℃的温度采样精度.依托光纤传感系统并运用数据采集与处理技术获得了在APD增益比较稳定的条件下其偏压与温度之间的线性关系以及增益温漂误差的偏压补偿公式,应用时传感系统能够实时补偿增益的温漂并且具有足以满足系统要求的补偿精度.     

雪崩光电二极管应用中的最佳噪声分配

导出了雪崩光电二极管应用中的最佳噪声分配关系式,据此提出了测量雪崩管最佳倍增特性的方法,并研制出了测量仪器,给出了雪崩光电二极管的测量结果.     

超晶格雪崩光电二极管的结构优化及性能研究

基于碰撞离化理论研究了异质材料超晶格结构对载流子离化率的作用,设计得到In0.53Ga0.47As/In0.52Al0.48As超晶格结构的雪崩光电二极管。通过分析不同结构参数对器件性能的影响,得到了低隧道电流、高倍增因子的超晶格结构雪崩层,根据电场分布方程模拟了器件二维电场分布对电荷层厚度及掺杂的依赖关系,并优化了吸收层的结构参数。对优化得到的器件结构进行仿真并实际制作了探测器件,进行光电特性测试,与同结构普通雪崩光电二极管相比,超晶格雪崩光电二极管具有更强的光电流响应,在12.5~20 V的雪崩倍增区,超晶格雪崩光电二极管在具备高倍增因子的同时具有较低的暗电流,提高了器件的信噪比。     

雪崩光电二极管最佳工作点的确定

本文根据雪崩管的倍增噪声特性,给出在最佳工作状态下,雪崩光电二极管的倍增噪声电流谱密度与放大器的等效输入噪声电流谱密度之间的数量关系,提出按照放大器本身的噪声电压在输出总噪声电压中所占的比例来确定雪崩光电二极管的最佳工作点的方法。用这种方法确定了厚耗尽层雪崩光电二极管的工作点,用该雪崩光电二级管作激光测距仪的探测器时,使测距仪的测程比用Pin硅光电二极管时提高一倍以上,接收灵敏度提高约二十八倍。     

MBE生长的PIN结构碲镉汞红外雪崩光电二极管

对中波红外碲镉汞雪崩光电二极管(APD)特性进行理论计算,获得材料的能量散射因子及电离阈值能级与材料特性的相互关系,从而计算器件的理论雪崩增益与击穿电压.通过对材料特性(组分,外延厚度,掺杂浓度等)的优化,设计并生长了适合制备PIN结构红外雪崩光电二极管的碲镉汞材料,并进行了器件验证.结果显示,在10V反偏电压下,该器件电流增益可达335.     

硅基雪崩光电二极管技术及应用

硅基雪崩光电二极管是一种可用于对微弱光甚至单光子进行探测的光电器件,被广泛应用于激光测距、激光成像、量子通信和生物医疗等领域。从工作原理、常见结构和分类3个方面对硅基雪崩光电二极管的技术进行分析,并对其性能发展趋势进行阐述,最后介绍了硅基雪崩光电二极管的应用。     

GaN基雪崩光电二极管及其研究进展

越来越多的民用与军事对高灵敏度紫外探测的需求促进了GaN基雪崩光电二极管（APD）的快速发展。雪崩光电二极管工作在高反偏电压状态,器件内部载流子在高场下发生碰撞离化,从而使探测信号产生增益。首先对GaN基雪崩光电二极管的研究进展进行了回顾,然后重点报道了器件的增益最大可达3105,介绍了本征层厚度与器件暗电流的关系,简单介绍了正在组建的基于相敏探测的交流增益测试系统,并研究了过剩噪声与调制频率之间的关系,发现在低频波段（30~2kHz）,过剩噪声呈现1/f噪声特性。最后,对盖革模式的雪崩光电二极管的研究进展及应用前景进行了简单介绍。     

激光测距应用中雪崩光电二极管最佳工作状态的再研究

回顾了雪崩光电二极管最佳工作状态的确定方法。根据R.J.McIntyre给出的关于达通型雪崩光电二极管的噪声谱密度结果,分析了不同背景下,确定最佳工作状态的最佳噪声分配比的特性,并给出了实验结果。给出了不但能确定和保持雪崩光电二极管的最佳工作状态,而且可以保持恒定的虚警率的实用方法。     

Noise Temperature Characteristics and Gain-control of Avalanche Photodiodes for Laser Radar

Avalanche photodiodes（APDs） are promising light sensors with high quantum efficiency and low noise. It has been extensively used in radiation detection, laser radar and other weak signal detection fields. Unlike other photodiodes, APD is a very sensitive light detector with very high internal gain. The basic theory shows that the gain of APD is related to the temperature. The internal gain fluctuates with the variation of temperature. Investigated was the influence of the variation of the gain induced by the fluctuation of temperature on the output from APD for a very weak laser pulse input in laser radar. An active reverse-biased voltage compensation method is used to stabilize the gain of APD. An APD model is setup to simulate the detection of light pulse signal. The avalanche process, various noises and temperature＇s effect are all included in the model. Our results show that for the detection of weak light signal such as in laser radar, even a very small fluctuation of temperature could cause a great effect on APD＇s gain. The results show that the signal-tonoise ratio of the APD＇s output could be improved effectively with the active gain-control system.     

InAs/InAsSb Avalanche Photodiode （APD） for applicaions in long-wavelength infrared region

A generic numerical model of a long-wavelength Avalanche Photodiode （APD） based on narrow bandgap semiconductor InAsSb on InAs substrate is reported for the first time. This model has been applied for theoretical characterization of a proposed N^＋ InAS/P-InAsSb avalanche photodiode structure for possible application in 2-5 μm wavelength region. The parameters such as gain, excess noise factor and their trade-off with variation of doping concentration and bias voltage have been estimated for the APD taking into account history-dependent theory of avalanche multiplication process, The LWIR APD is expected to fred application in optical gas sensor and in future generation of optical communication system.     

Degradation behavior of avalanche photodiodes with a mesa structure observed using a digital OBIC monitor

The degradation behavior of avalanche photodiodes (APDs) with a mesa structure during bias-temperature aging is investigated. The dark-current variation using the optical-beam-induced current (OBIC) imaging technique is analyzed. A rise in the induced photocurrent was observed when the diodes were biased below the reach-through voltage indicating degradation, and the current path localized at the mesa edge of the absorption layer. The APD dark-current deterioration is well correlated with the OBIC observation, and the surface potential change near the mesa-edge surface is the most plausible cause of the deterioration. An APD with a lifetime exceeding 200 000 h at 85 /spl deg/C, which is a sufficient reliability for receiver applications, has been achieved by preventing the degradation.     

雪崩光电二极管电外差混频技术及其参量优化

雪崩光电二极管(APD)具有频响宽、灵敏度高的优点,在激光测距中有重要应用.为了分析APD电外差混频技术对系统信噪比的影响,建立了APD的数学模型,仿真分析了偏置电压直流分量与信噪比的关系,以及APD击穿电压变化时对信噪比的影响.结果表明,APD电外差混频技术会降低APD输出信号的信噪比,但它降低了后续电路处理带宽,有利于系统整体信噪比的提升;当APD输入光信号较微弱时,采用电外差混频技术,可有效提高系统整体的信噪比.     

A simplified approach to time-domain modeling of avalanchephotodiodes

A simplified algorithm for calculating time response of avalanche photodiodes (APDs) is presented. The algorithm considers the time course of avalanche processes for the general case of position-dependent double-carrier multiplications including the dead space effect. The algorithm is based on a discrete time setting ideally suited for computer modeling and can be applied to any APD structure. It gives a fast and accurate estimation of the time and frequency response of APDs. As an example, the present method is applied to InP-InGaAs separate absorption, grading, charge, and multiplication (SAGCM) APDs. The variation of multiplication pain with bias voltage and 3-dB electrical bandwidth at different multiplication gain obtained using the new algorithm show good agreement with experimental results. The algorithm can be used to study temperature dependence of APD characteristics and can be easily extended to calculate the excess noise factor     

Effect of doping on the reliability of GaAs multiple quantum wellavalanche photodiodes

The effect of various doping methods on the reliability of gallium arsenide/aluminum gallium (GaAs/AlGaAs) multiple quantum well (MQW) photodiode (APD) structures fabricated by molecular beam epitaxy is investigated. Reliability is examined by accelerated life tests by monitoring dark current and breakdown voltage. Median device lifetime and the activation energy of the degradation mechanism are computed for undoped, doped-barrier, and doped-well APD structures. Lifetimes for each device structure are examined via a statistically designed experiment. Analysis of variance (ANOVA) shows that dark current is affected primarily by device diameter, temperature and stressing time, and breakdown voltage depends on the diameter, stressing time, and APD type. It is concluded that the undoped APD has the highest reliability, followed by the doped-well and doped-barrier devices, respectively. To determine the source of the degradation mechanism for each device structure, failure analysis using the electron-beam induced current method is performed. This analysis reveals some degree of device degradation caused by ionic impurities in the passivation layer, and energy-dispersive spectrometry subsequently verifies the presence of ionic sodium as the primary contaminant. However since all device structures are similarly passivated, sodium contamination alone does not account for the observed variation between the differently doped APD's. This effect is explained by dopant migration during stressing, which is verified by free carrier concentration measurements using the capacitance-voltage (C-V) technique     

A Resilient and Power-Efficient Automatic-Power-Down Sense Amplifier for SRAM Design

A conventional latch-type sense amplifier in a static random access memory (SRAM) could trigger sensing failure under severe process variation. On the other hand, a traditional current-mirror sense amplifier could consume too much power. To strike a good balance, this paper presents an automatic-power-down (APD) sense amplifier, which can avoid sensing failure while keeping the power dissipation low. In this scheme, the operation window of the sense amplifier is adaptive to the real silicon speed of its associated column through Schmitt–Trigger-based dual-$V _{rm HL}$ APD circuitry. A 64-kb SRAM design using the proposed technique in a 22-nm predictive technology model demonstrates that a power savings of 28%–87% over the traditional current-mirror sense amplifier is achievable.      

用于APD激光探测的电荷灵敏前置放大器设计

雪崩光电二极管（APD）作为探测元件实现光电转换广泛应用于激光脉冲探测技术中。前置放大器是影响APD激光脉冲探测系统好坏的关键因素,前置放大器的信噪比决定了整个探测系统的信噪比优劣。提出了电荷灵敏前置放大器应用于APD激光脉冲探测系统以提高探测距离和探测精度的方法。讨论了激光脉冲探测技术和APD特性,在此基础上设计了以结型场效应管和集成运放为主要器件的低噪声电荷灵敏前置放大器电路并对设计电路进行了实验分析。实验结果表明：将电荷灵敏前置放大器应用于APD激光脉冲探测系统可以有效提高系统的信噪比,改善激光探测性能。     

硅基APD器件的工艺及性能仿真分析

硅基APD 的性能取决于其器件结构与工艺过程。文中对n+-p--p+外延结构的APD 器件的工艺和器件性能进行了仿真分析,为硅基APD 器件的设计提供了理论指导。利用Silvaco 软件对APD器件的关键工艺离子注入和扩散工艺进行了仿真, 确定工艺参数对杂质的掺杂深度和掺杂分布的影响。并且,对于APD 器件的性能进行了分析,对电场分布、增益、量子效率、响应度等参数进行了仿真分析。仿真结果表明:在给定的器件参数条件下,所设计的APD器件的增益为100时,响应度峰值为55A/W左右,在600~900 nm 范围内具有较高响应度,峰值波长在810 nm。     

碲镉汞雪崩光电二极管在激光雷达上的应用

首先简要介绍激光雷达的主要军事应用、激光雷达对接收器的性能需求及激光雷达接收器的现状,综述碲镉汞材料特点、碲镉汞雪崩光电二极管探测器特点,与现有激光雷达接收器相比碲镉汞雪崩光电二极管作为激光雷达接收器的优势及制备技术;综述国外碲镉汞雪崩光电二极管用于激光雷达接收器的发展现状;最后分析我国发展用于激光雷达接收器的碲镉汞雪崩光电二极管可行性。