Large-Format Voltage-Tunable Dual-Color Midwavelength Infrared Quantum-Well Infrared Photodetector Focal Plane Array

We report a large-format (640 times 512) voltage-tunable quantum-well infrared photodetector (QWIP) focal plane array (FPA) for dual-color imaging in the midwavelength infrared (3-5 mum) band. Voltage-tunable spectral response has been achieved through series connection of two eight-well stacks of AlGaAs-InGaAs epilayers grown by molecular beam epitaxy on GaAs substrate. The peak responsivity wavelength of the detectors is shifted from 4.1 mum (color 1) to 4.7 mum (color 2) as the bias is increased within the limit applicable by commercial read-out integrated circuits. The operability of the FPA is ~99.5% with noise equivalent temperature differences of ~60 and 30 mK (f/1.5) in color modes 1 and 2, respectively. To our knowledge, this is the first large-format voltage-tunable dual-color QWIP FPA reported for midwavelength thermal imaging.     

Comparison of Long-Wave Infrared Quantum-Dots-in-a-Well and Quantum-Well Focal Plane Arrays

This paper reports on a comparison between a commercially available quantum-well infrared focal plane array (FPA) and a custom quantum-dot (QD)-in-a-well (DWELL) infrared FPA in the long-wave infrared (LWIR). The DWELL detectors consist of an active region composed of InAs QDs embedded in $ hbox{In}_{.15}hbox{Ga}_{.85}hbox{As}$ quantum wells. DWELL samples were grown using molecular beam epitaxy and fabricated into 320 $times$ 256 pixels FPA with a flip-chip indium bump technique. Both the DWELL and QmagiQ commercial quantum-well detector were hybridized to an Indigo ISC9705 readout circuit and tested in the same camera system. Calibrated blackbody measurements at a device temperature of 60 K with LWIR optics yield a noise equivalent change in temperature of 17 mK and 91 mK for quantum-well and DWELL FPAs operating at 0.95- and 0.58-V biases, respectively. The comparison of the DWELL and quantum-well FPA when imaging a 35 $^{circ}hbox{C}$ black body showed that the DWELL had a signal-to-noise ratio of 124 while the quantum-well FPA showed 1961. As well, the quantum-well FPA showed a higher collection efficiency of 1.3 compared to the DWELL.      

Large-Format Voltage-Tunable Dual-Band Quantum-Well Infrared Photodetector Focal Plane Array for Third-Generation Thermal Imagers

We report a large-format (640 times 512) voltage- tunable quantum-well (QW) infrared photodetector focal plane array (FPA) for dual-band imaging in the mid- and long-wavelength infrared (MWIR and LWIR) bands. Voltage-tunable spectral response has been achieved through a series connection of eight-well MWIR AlGaAs-InGaAs and 16-well LWIR AlGaAs-GaAs QW stacks grown by molecular beam epitaxy on GaAs substrate. The peak responsivity wavelength of the detectors is shifted from 4.8 to 8.4 mum as the bias is increased within the limit applicable by commercial read-out integrated circuits. The FPA with MWIR and LWIR cutoff wavelengths of 5.1 and 8.9 mum provides noise equivalent temperature differences of 20 and 32 mK (f/1.5) in these bands, respectively. The results are very encouraging for the development of low-cost large-format dual-band MWIR/LWIR FPA technology.     

测辐射热计红外焦平面列阵

非制冷测辐射热计红外焦平面列阵设计为桥式结构,器件制作采用微机械加工技术。工作被段为８￣１２μｍ,热阻达１０＾７Ｋ／Ｗ量级,噪声等效温差为０．１Ｋ。     

非致冷测辐射热计红外焦平面阵列

非致冷测辐射热计以其高性能和低价格 ,成为红外热成像技术新的研究热点。焦平面设计为桥式结构 ,器件制作采用微机械加工技术。文章介绍了该器件的设计、制作、性能和应用。     

Demonstration and Performance Assessment of Large Format InP–InGaAsP Quantum-Well Infrared Photodetector Focal Plane Array

There have been various studies showing that InP-InGaAs quantum-well infrared photodetectors (QWIPs) are potential alternatives to AlGaAs-GaAs QWIPs in the long wavelength infrared (LWIR) band, especially for applications requiring high responsivity. Being on InP substrate, this material system also offers lattice matched mid-wavelength infrared (MWIR)/LWIR dual band QWIP stack when it is used with the AlInAs-InGaAs system. It is desirable to extend the cut-off wavelength of InP based LWIR QWIPs to , which can be accomplished by replacing the QW material with InGaAsP. In this paper, we report the first InP-InGaAsP QWIP focal plane array (FPA). The 640 512 FPA displayed remarkably low noise equivalent temperature difference (NETD) with very short integration times (46 mK at 66 K with and f/1.5 optics). The results show that these QWIPs can be operated with high responsivity (1 A/W) while offering bias adjustable gain in a wide range where the detectivity is almost constant at a reasonably high level.     

非致冷红外焦平面阵列用探测材料

非致冷红外焦平面阵列以其高密度、高性能和低成本,成为当前红外热成像技术的研究重点;而探测材料是非致冷红外焦平面阵列的基础。本文重点介绍了目前比较成功的三类非致冷红外焦平面阵列——热电堆型、热敏电阻型和热释电型,在开发过程中所采用的各种探测材料。     

红外焦平面阵列盲元检测技术研究

盲元的数量及其分布对红外焦平面阵列器件成像质量的影响较大.在给出盲元定义的基础上,对盲元的各种产生机理进行了分析,并给出了具体的盲元检测方法,为盲元补偿技术的研究提供了理论基础.     

红外焦平面阵列器件非均匀性分析

红外焦平面阵列固有的非均匀性严重地制约着其成像系统的成像质量,必须对其进行补偿校正。在深入地研究了非均匀性的各种来源及其表现形式的基础上,论述了校正原理,并提出了一种普遍适用的测量方法。     

国外长波红外焦平面列阵现状

文中介绍了长波工外焦平面列阵的国外进展，这些列阵包括碲镉汞光电二极管、肖特基势垒器件、砷化镓／砷铝镓多量子阱光导体、高温超导体以及室温工作的焦平面列阵，其中非制冷的混合式热释电陶瓷和单片式的微型测辐射热计焦平面列阵已进入批理生产阶段。     

红外焦平面阵列非均匀性仿真技术研究

红外焦平面阵列非均匀性的建模和仿真,是红外成像系统仿真中很关键的一部分.根据红外焦平面阵列非均匀性产生的原因和特点,建立了基于空间相关性的探测器响应模型,较基于各探测元间是独立不相关假设下的响应模型更为科学客观.     

Monolithic Integration of Diffractive Microlens Arrays and Infrared Focal Plane Arrays

Monolithic integration method has been demonstrated to increase the fill factor of the infrared focal plane arrays (IRFPA). Which is consists of 256×256 Pt-Si schottky barrier charge coupled devices(CCD) operation in 3-5μm IR region. The relative silicon 256×256 element diffractive microlens arrays have been fabricated on the back side of the substrate of the IRFPA using binary optics technology. The aligning process between IRFPA and microlens arrays on each side of the substrate has been completed by IR mask aligner. The testing results show that the imaging quality is very good and the average optical response of the IR FPA is increased by a factor of 3.0, which is improved by about 25% compared with the hybrid integration method in the previous work.     

红外焦平面失效现象仿真研究

在性能较差的红外焦平面器件中，其背景图像经常出现一些现象，比如“黑线”、“锯齿”、“滴落圆”等，其原因可能是红外焦平面器件有缺陷或其读出电路存在问题。本文针对红外焦平面可能出现的各种缺陷，将其等效为失效性模型，用EDA软件分别对采用DI和CTIA两种读出结构的红外焦平面进行失效性等效模拟分析。通过对3×3和10×10规模的红外焦平面输出信号进行模拟，分析了背景图像中失效现象产生的原因。红外焦平面失效现象模拟分析得出的结果，为红外焦平面读出电路结构的改进提供了参考依据。     

PtSi红外焦平面阵列技术的发展概况

介绍了PtSi肖特基势垒红外焦平面阵列技术的最新进展,分析了国内研究中存在的问题,并指出了今后的发展方向     

红外焦平面失效现象仿真研究

在性能较差的红外焦平面器件中,其背景图像经常出现一些现象,比如"黑线"、"锯齿"、"滴落圆"等,其原因可能是红外焦平面器件有缺陷或其读出电路存在问题.本文针对红外焦平面可能出现的各种缺陷,将其等效为失效性模型,用EDA软件分别对采用DI和CTIA两种读出结构的红外焦平面进行失效性等效模拟分析.通过对3×3和10×10规模的红外焦平面输出信号进行模拟,分析了背景图像中失效现象产生的原因.红外焦平面失效现象模拟分析得出的结果,为红外焦平面读出电路结构的改进提供了参考依据.     

Optimal Doping Density for Quantum-Well Infrared Photodetector Performance

We present a systematic study on a set of n-type GaAs-AlGaAs quantum-well infrared photodetectors (QWIPs) with varying Si doping density in the wells. It is revealed that the increase in doping density enhances proportionally the absorption efficiency and responsivity while increasing exponentially the dark current and hence the dark current noise. We experimentally confirm the theoretically predicted optimum conditions for background-limited infrared performance temperature and detector-noise-limited detectivity. It is suggested that, to achieve the optimal QWIP performance, the doping density in the wells should be determined according to application and the desired operating temperature. We point out that a simulation is highly recommended to achieve the best possible performance since the choice of doping may not be obvious. As shown here, an optimized doping for temperature is actually the worst for detectivity for the particular set of samples.     

非致冷红外焦平面阵列读出电路的噪声抑制

读出电路(ROIC)是非致冷红外焦平面阵列器件(UIRFPA)的关键组成部分之一。RO-IC性能的好坏直接影响到UIRFPA的性能,非致冷红外焦平面阵列读出电路的噪声抑制也是一个研究的热点。文章探讨了非致冷红外焦平面阵列读出电路的噪声及抑制方法。仿真实验结果表明,该方法具有一定的先进性。     

红外焦平面阵列盲元补偿算法研究

提出了一种补偿盲元的新算法,它首先利用自适应中值滤波检测红外焦平面阵列上可能的盲元点,然后再使用细节保持变分法对所挑出的盲元点进行补偿.这样,由于既保护了边缘又抑制了噪声,因此恢复出的图像质量明显优于传统的平滑滤波方法.仿真结果表明,本算法对噪声水平为25%的图像进行恢复后,其峰值信噪比仍可达到34.918 dB.     

单片式PtSi肖特基势垒IR—ITCCD焦平面列阵

本文介绍了PtSi肖特基势垒IRCCD的工作原理,评述了国外硅化物肖特基势垒红外焦平面列阵的发展,重点阐述了已制成的64×64、128×128元PtSi肖特基势垒IR-ITCCD焦平面列阵的结构与设计思想。     

Kalman-Filtering红外焦平面非均匀性仿真研究

非均匀性红外图像的仿真技术,在非均匀性校正技术的研究中起着十分重要的作用.针对红外探测器的响应参数符合高斯-马尔可夫(Gauss-Markov)过程,引入一个线性响应模型,建立了状态方程和观测方程,进而在一定的初始条件下,使用卡尔曼滤波(Kalman-Filtering)的方法,完成了红外图像的仿真计算.仿真的红外图像经过理论分析,效果很理想.