二极管原理非制冷红外焦平面阵列的集成设计

面向非制冷红外成像的低成本高性能应用,二极管原理的红外焦平面阵列的设计和工艺实现得到研究和发展.焦平面和读出电路的设计集成以及CMOS和MEMS工艺集成是此项技术的研究重点.基于SOI的二极管原理焦平面阵列在低成本的利用CMOS工艺实现大规模阵列集成方面有很大的优势.读出电路是基于标准CMOS工艺进行设计的.320×2...     

论红外焦平面器件的串音

红外探测系统通常需要将探测器密集排列以增加它们的空间分辨率。在焦平面阵列中,当投射到某一特定探测器光敏面上的红外光子在另一个探测器中产生信号时,这种现象称为串音。串音可能会影响焦平面阵列的分辨率性能。在高性能光伏阵列中,串音的主要成分是光生载流子在焦平面阵列的相邻探测器之间的横向扩散。从基本概念入手,介绍了相关串音研究的发展情况以及对串音问题的理解和体会。     

Hybrid Integration Between Long Focus Microlens Array and IR Detector Array

A special method, named step simulation method, is proposed for fabricating Si microlens array to improve the performance of infrared focal plane array (IR FPA). The focus length of rectangle-based multistep microlens array with element dimension of 40 µm×30 µm is 885.4 µm by the method, which is much longer than the focus length of microlens array fabricated by conventional Fresnel binary optics technique., The large-scale 256×256 element microlens array is hybridintegrated with the PtSi Schottky-barrier IR FPA by optical adhesive. The test results show that diffractive spot size of the microlens is 17 µm×15 µm and the average optical response of the IR FPA is increased by a factor of 2.4.     

基于扫描面阵的红外预警系统及其探测性能分析

目前红外搜索跟踪(IRST)系统普遍采用红外焦平面传感器,线阵FPA使系统达到了更高的灵敏度和分辨率.然而由于线阵FPA扫描系统的固有限制,IRST系统不能实现任意方位的潜在目标跟踪,而采用面阵FPA的IRST系统可以较好的解决这些问题,但帧积分时间内探测器的扫描运动使图像存在严重的拖尾,给目标探测带来了影响.介绍了一种基于面阵FPA的全方位红外预警系统设计,并对采用线阵和面阵FPA探测器的系统性能进行了对比分析.提出通过目标能量累积技术弥补目标拖尾对面阵FPA扫描系统探测性能的影响,实验验证了能量累积技术可以使面阵IRST达到接近线阵IRST的探测距离,同时具有更低的虚警率.     

Long-Term Stability of a 640 × 512 InSb Focal Plane Array with a Pitch of 15 μm

The long-term stability of a 640x512 InSb focal plane array (FPA) with a pitch of 15 μm combined with a Stirling cooler and an interface block has been investigated.The dependences of the FPA correctability index on the operation time after a two-point correction of the irregularity have been obtained. The FPAs with two different circuits of the readout LSI cells that differ in the integration capacitance and transmission coefficients are considered. It has been found that, for the InSb FPA, the long-term stability is as high as several hours, which ensures continuous operation of the array in thermal imaging systems without additional calibrations.     

A terahertz focal plane array using HEB superconducting mixers and MMIC IF amplifiers

We present a focal plane array (FPA) designed for operation at terahertz frequencies. The FPA is based on NbN phonon-cooled hot electron bolometer mixers directly coupled to wide-band microwave monolithic integrated circuit IF amplifiers. The array incorporates all the required dc-bias and IF circuitry in a compact split-block design. We present new experimental results describing the optical coupling efficiency to the array, as well as receiver noise temperature measurements. The measurements were performed at 1.6 THz, showing good agreement with theoretical predictions. This is the first low-noise heterodyne focal plane array to be reported for any frequency above 1 THz.     

短波红外InGaAs焦平面研究进展

围绕新一代遥感探测仪器应用需求,中国科学院上海技术物理研究所在短波红外InGaAs焦平面探测器领域取得了一系列进展.通过低缺陷外延材料、焦平面芯片制备工艺和低噪声读出电路技术研究,研制实现了最大规模达2560×2048元的10μm中心距1～1.7μm InGaAs焦平面探测器,峰值探测率优于1.0×1013 cmHz1...     

基于光学读出非制冷红外成像系统的无基底FPA等效电学模型

与传统的有基底FPA(焦平面阵列)相比, 基于全镂空支撑框架结构的新型无基底FPA在热学特性上存在显著差异, 传统的基于恒温基底假设的热学分析模型不再适用, 因此, 通过电学比拟方法, 将无基底FPA的热响应特性等效为电学模型.通过该模型, 进一步分析了无基底FPA在非真空环境下的热学性能, 分析表明: 该无基底FPA具有在大气压下优良的红外成像性能, 其NETD(噪声等效温度差)值仅比真空环境下增加了数倍.     

640×512偏振长波量子阱红外焦平面探测器研制

介绍了大面阵偏振长波量子阱红外焦平面探测器组件的研制进展。在640512规模20 m中心距面阵上,偏振焦平面采用了22子单元设计,子单元中每个像元分别刻蚀0、90、45以及135方向的一维线性光栅,来获得入射光不同偏振角度的信息。突破了长波量子阱材料外延和器件制备等关键技术,制备出面阵探测器芯片,实现了偏振长波红外探测的单片集成,配上杜瓦和制冷机,研制出噪声等效温差优于30 mK的长波偏振640512量子阱探测器组件。     

室温型热释电红外探测器焦平面列阵新进展

文中介绍了目前室温工作的热释电红外探测器焦平面列阵的国外进展，混合型铁电陶瓷焦平面列阵已进入批量生产阶段，这类焦平面列阵制作的热像仪已于１９９５年进入商品市场，而单片式铁电薄膜红外探测器焦平面列阵还处在实验室研究阶段。     

Optical readout uncooled infrared imaging detector using knife-edge filter operation

An optical readout uncooled infrared (IR) imaging detector of bimaterial cantilever array using knife-edge filter operation (KEFO) is demonstrated. The angle change of each cantilever in a focal plane array (FPA) can be simultaneously detected with a resolution of 10-5 degree. A deformation magnifying substrate-free micro-cantilever unit with multi-fold interval metallized legs is specially designed and modeled. A FPA with 160×160 pixels is fabricated and thermal images with noise equivalent temperature difference (NETD) of 400 mK are obtained by this imaging detector.     

红外焦平面探测器非线性度拟合参数分析

从理论上分析了光子型红外焦平面探测器各输入输出参数之间的线性关系.对典型320×256长波红外焦平面探测器在不同拟合参数下的非线性度进行了测试,并与理论计算结果进行了比较.结果表明采用输出信号电压与波段光子数或黑体波段辐照功率进行拟合,可以使理论上带来的非线性度减至最小,能够更为准确地评价红外焦平面探测器的非线性度.     

Investigation of planar photodiodes of a focal plane array based on a heteroepitaxial InGaAs/InP structure

The results of investigation of planar photodiodes (PDs) in a focal plane array (FPA) based on a heteroepitaxial InGaAs/InP structure are reported. The FPA has a size of 320 × 256 elements with a pitch of 30 μm, which are hybridized with various ROIC readout circuits. It is demonstrated that the PD reverse bias should be no lower than 2 V in order to suppress the FPA intercoupling at the room temperature. It is found that the dark current may be reduced considerably by cooling the FPA to–20°С with a two-stage thermoelectric cooler. The best average room-temperature dark current over the FPA planar photodiodes is 0.22 pA at an optimum PD bias of–2.4 V.     

Decoupling Efficiency of a Wideband Vivaldi Focal Plane Array Feeding a Reflector Antenna

A focal plane array (FPA) feeding a reflector can be used to achieve a large field of view (FOV) with overlapping simultaneous beams. In order to provide a continuous FOV over more than an octave bandwidth, the inter-element spacing in the FPA has to be electrically small over large parts of the band. This will inevitably result in strong mutual coupling effects between the array elements. On transmit, the total lost power due to mutual coupling can be quantified by the decoupling efficiency, a term recently introduced for antenna arrays. This paper presents measured decoupling efficiencies of a Vivaldi element FPA operating between 2.3 and 7 GHz. The radiation patterns of the FPA are calculated for two beam excitations by using measured embedded element patterns, and the corresponding decoupling efficiencies are evaluated by using measured $S$ -parameters between all element ports. The FPA is assumed to illuminate a deep reflector with $F/D=0.35$ , and the overall reflector aperture efficiencies are computed. The decoupling efficiencies are also determined through the measurements of the total radiation efficiencies in a reverberation chamber, which includes material absorption losses.      

多波段热成像阿基米德螺旋线推扫滤光盘工程设计

将阿基米德螺旋线近似逐行推扫的滤光方式与非制冷焦平面探测器(FPA)逐行积分读出进行同步,滤光当前行的同时读出上一行的数据,可改善分时滤光多波段热成像系统的FPA使用效率,从而提高系统帧率.本文从工程应用的角度出发,对阿基米德螺旋线滤光盘(阿盘)的多波段滤光、推扫滤光与FPA逐行读出的时间同步、多波段序列图像的帧识别、阿盘的整机集成等问题进行探讨,为新型多波段热成像系统的设计提供工程经验.     

大周长面积比延伸波长InGaAs红外焦平面噪声

在理论上分析了红外焦平面组件中光敏元、读出电路以及两者耦合的总噪声特性,对大周长面积比(38×500μm2)延伸波长InGaAs组件的噪声与温度、积分时间的关系进行了实验和分析.实验结果指出,在一定条件下组件噪声与积分时间的根号并不成正比.测量了不同温度下的组件暗信号、噪声,得到组件噪声与暗电流的关系,分析表明,该种组件噪声主要来自于1/f噪声及读出电路输入级电流噪声.     

320×256 GaAs/AlGaAs长波红外量子阱焦平面探测器

量子阱红外探测器(Quantum well infrared photodetector, QWIP)已经经历了20多年的深入研究,各种QWIP器件,包括量子阱红外探测器焦平面阵列(FPA)的研制也已经相当成熟。但是在国内,受制于整体工业水平, QWIP焦平面阵列器件的研制仍然处于起步阶段。研制了基于GaAs/ AlxGa1-xAs 材料、峰值响应波长为9.9 m的长波320256 n型QWIP焦平面阵列器件,其像元中心距25 m, 光敏元面积为22 m22 m。GaAs衬底减薄后的QWIP焦平面阵列,与Si基CMOS读出电路(ROIC)通过铟柱倒焊互连,并且在65 K工作温度下进行了室温环境目标成像。该焦平面器件的规模和成像质量相比之前国内报道的结果都有较大提高。焦平面平均峰值探测率达1.51010 cmHz1/2/W。     

320 × 240 CMOS array for the spectral range of 3–5 μm based on PtSi photodiodes

The results of research and development of a 320 × 240 platinum silicide focal plane array (FPA) for the spectral range of 3–5 μm are presented. The development is based entirely on CMOS technology. It is shown that the FPA makes it possible to adjust the photosignal accumulation time at a fixed frame rate and subtract the background constant component in the output device.     

InSb面阵探测器波段内脉冲激光干扰响应特性研究

介绍了激光定向干扰红外探测系统的干扰机理及波段内激光定向干扰的主要干扰方式.以InSb红外探测成像系统为研究对象,开展了典型条件下的波段内脉冲激光定向干扰试验,分析了InSb面阵探测器对波段内脉冲激光干扰的响应特性,获取了探测器在脉冲激光干扰下的损伤模式和损伤阈值,为后续深入研究激光定向干扰效能奠定基础.     

提高红外图像均匀性的两级校正技术研究

凝视红外焦平面成像系统中经常需要根据目标红外辐射强度来修改探测器积分时间,当积分时间变化后,红外图像的均匀性明显变差。探索了一种利用积分时间校正与目前实用性较好的两点温度定标法相结合的焦平面非均匀性校正方案,不仅使红外图像的均匀性得到较大幅度提高,而且在修改积分时间的情况下图像均匀性不受影响。