TEC Colling Shortwave Infrared 320×256 Focal Plane Detector

The short-wave HgCdTe thin film material was grown by liquid phase epitaxy on CdTe substrate,Adopt n on p injection bonding and function and flip-flop mixing process,With a low noise readout circuit,sealed with a high airtightness cellular-metal shell,Using a four-stage Thermo Electric Cooler(TEC),320×256 Short Wave Infrared Focal Plane Cooling Detecto r available to operate at near room temperature(210K).Its main photoelectric performance are signal-to-noise ratio greater than 400,nonuniformity equivalent to 4.69%,operability equivalent to 99.76%,frame rate equivalent to 115Hz,component weight less than 150grams.

Ge-based Medium Wave Infrared MCT 1280×1024 Focal Plane Detector

Medium-wave HgCdTe thin films grown on germanium-based substrates by molecular beam epitaxy were treated by large area n-on-p injection junction and flip-flop mixing process.The chips interconnected with low-noise and multimodal options readout circuit composed a 1280×1024 Medium-wave Infrared Focal Plane Cooling Detector whose pixel spacing was 15 microns.Its main photoelectric properties are average NETD equivalent to 18.5 mK,non-uniformity equivalent to 7.5%,operability equivalent to 98.97%.The paper also studies the substrate-removal technique on Germanium-based chip,which improves the stability and reliability of detector.

A Heavy Ion Focal Plane Detector for Beijing Q3D Magnetic Spectrometer

A semi-length focal plane detecting system for heavy ions has been built onthe Beijing Q3D magnetic spectrometer and tested by 12C+197Au,16O+150Sm,and 18O-156Gd reactions.The intrinsic resolutions of position and angle were 1.1 mmand 0.8°,respectively.The resolutions of energy loss ΔE,residual energy ER and totalenergy ET obtained were 3.0%,1.4% and 0.9%.respectively,after a special method ofdata processing was adopted.The achievable mass resolution is estimated to be about1.0% after necessary corrections for some signals concerned.Discussion aboul the edgeeffect of the detectors of this type is given too.

Development and evaluation of a double-plane detector system for multi-radionuclide imaging

Purpose To develop a multi-radionuclide imaging system with a flexible and compact structure that has a potential for breast and other applications,and to evaluate its performances under both positron emission tomography and single photon emission imaging conditions.Methods The plane detector was composed of 5×6 blocks with an effective detection area of 168.6 mm×202.4 mm.Each block consisted of a 16×16 LYSO array.The pixel size is 1.9 mm×1.9 mm×15 mm.An 8×8 silicon photomultiplier(SiPM)array with SensL’s C-30035 sensors was coupled to the LYSO array,separated by a 1.5-mm-thick glass.To minimize the influence of temperature on the detector,the active part of the front-end electronics was kept away from SiPMs.Self-designed data acquisition system and reconstruction software were utilized to evaluate the performances of the whole system.Results All the blocks had excellent pixels identification.An average energy resolution of 11.39%for 511 keV and 21.37%for 140 keV was obtained.In the PET mode,the best spatial resolution was better than 2 mm and the system sensitivity reached up to 11.05%at 60 mm distance.In the single photon emission imaging mode,a spatial resolution better than 3 mm was obtained.Conclusion The results indicated that the system has a good overall performance and can be used in breast imaging and other general PET applications.It also has the potential to be used for single photon emission imaging.In pursuit of a better spatial resolution of cross-plane,PSF and DOI technology will be developed in the next work.For specific applications,further improvement of the detector system such as performance evaluation with phantoms will be carried out.

Research on the Arrangement of Dew Point Temperature Detectors of Capillary Plane Radiation Air-Conditioning

Based on analysis of the reason and process of condensation on ceiling radiant cooling panels, two kinds of arrangement of detectors are put forward. The physical model is established, the results show that detectors are arranged as the form of triangle is more suitable. It can not only satisfy the use requirement but also it is economical and practical. Finally we can conclude that the inlet water temperature 0.5°C higher than dew point temperature is safe and reliable.

Design and Imaging Application of Room-Temperature Terahertz Detector with Micro-Bolometer Focal Plane Array

Room-temperature terahertz （THz） detectors indicate a great potential in the imaging application because of their real-time, compact bulk, and wide spectral band responding characteristics. THz detectors with different dimensions based on a micro-bridge structure have been designed and fabricated to get optimized micro-bolometer parameters from the test results of membrane deformation. A nanostructured titanium （Ti） thin film absorber is integrated in the micro-bridge structure of the VOx micro-bolometer by a combined process of magnetron sputtering and reactive ion etching （RIE）, and its improvement of THz absorption is verified by an optical characteristics mesurement. Continuous-wave THz detection and imaging are demonstrated by using a 2.52 THz far infrared CO2 laser and a 320x240 vanadium oxide micro-bolometer focal plane array with an optimized cell structure. With this detecting system, THz imaging of metal concealed in a wiping cloth and an envelope is demonstrated, respectively.

中波红外640×512(25μm)探测器组件可靠性验证试验

随着红外探测器技术的发展,对探测器组件的可靠性提出了更高的要求。探测器可靠性随整机考核的方法难以满足考核需求,针对该问题,开展了中波红外640×512(25μm)探测器组件在环境应力下的可靠性验证研究,对探测器组件中的关键部位进行了高温加速寿命试验、持续工作等试验,并根据关键部件专项可靠性试验数据对探测器组件的整体可靠性进行预计,结合所选择的可靠性评估方法,对试验结果进行评估,评估结果表明所研制的组件满足可靠性要求。所使用的可靠性验证及评估方法,可以对制冷型红外探测器组件做出较为客观、准确的评估。

基于单个宽频CMOS探测器的太赫兹焦平面扫描成像系统

太赫兹波是介于毫米波与红外光之间的电磁波,具有强穿透性、非电离性、高瞬时带宽等特点,在安全检查、无损检测、医疗成像等领域有着广阔的应用前景。在成像系统中,探测器是至关重要的部分。本文提出了一种将不同中心频率的窄带探测器输出结合实现宽频带探测的结构,为了减少面积,这些窄带探测器采用嵌套式结构,即高频窄带探测器被依次放置在低频窄带探测器的内部,每一个窄带探测器均包括环形天线、匹配网络和场效应晶体管检波电路。该探测器由65 nm标准CMOS工艺制成,探测频率范围覆盖了100~1000 GHz。基于该宽频探测器搭建实现了太赫兹焦平面成像系统,该系统主要包括太赫兹辐射源、聚四氟乙烯(PTFE)透镜、宽频CMOS探测器等。实验结果表明,该成像系统在100 GHz、220 GHz和300 GHz频率下能够稳定成像,并且随着频率的提高,成像质量也明显提升。通过对得到的成像结果使用形态学闭运算进行优化,解决了成像中信息缺失的问题,有效地改善了成像质量。

冷屏对红外焦平面探测器组件性能的影响

分析了国内早期中波320×256红外焦平面探测器组件与国外同类产品在装机性能上的差异,采用三种实验方法检测了国内外探测器组件的光电性能,通过对探测器组件光电转换和结构的分析,确定出杂散光在冷屏内部的反射是导致测试结果差异的原因,冷屏内表面黑化层和结构形式是影响组件实际应用的关键。冷屏结构改进后,有效改善了国内探测器组件的实际应用性能。

Thermal and mechanical characterizations of a substrate-free focal plane array

We propose a substrate-free focal plane array （FPA） and the microcantilevers extend from a supporting frame. in this paper. The solid substrate is completely removed, Using finite element analysis, the thermal and mechanical characterizations of the substrate-free FPA are presented. Because of the large decrease in thermal conductance, the supporting frame is temperature dependent, which brings out a unique feature： the lower the thermal conductance of the supporting frame is, the higher the energy conversion efficiency in the substrate-free FPA will be. The results from the finite element analyses are consistent with our measurements： two types of substrate-free FPAs with pixel sizes of 200×200 and 60×60 um^2 are implemented in the proposed infrared detector. The noise equivalent temperature difference （NETD） values are experimentally measured to be 520 and 300 mK respectively. Further refinements are considered in various aspects, and the substrate-free FPA with a pixel size of 30×30 um^2 has a potential of achieving an NETD value of 10 mK.

DUAL-BAND INFRARED DETECTORS

As the infrared technology continues to advance, there is a growing demand for multispectral detectors for advanced IR systems with better target discrimination and identification. Both HgCdTe detectors and quantum well GaAs/AlGaAs photodetectors offer wavelength flexibility from medium wavelength to very long wavelength and multicolor capability in these regions. The main challenges facing all multicolor devices are more complicated device structtures, thicker and multilayer material growth, and more difficult device fabrication, especially when the array size gets larger and pixel size gets smaller. In the paper recent progress in development of two color HgCdTe photodiodes and quantum well infrared photodetectors is presented. More attention is devoted to HgCdTe detectors. The two color detector arrays are based upon an n P N (the capital letters mean the materials with larger bandgap energy) HgCdTe triple layer heterojunction design. Vertically stacking the two p n junctions permits incorporation of both detectros into a single pixel. Both sequential mode and simultaneous mode detectors are fabricated. The mode of detection is determined by the fabrication process of the multilayer materials. Also the performances of stacked multicolor QWIPs detectors are presented. For multicolor arrays, QWIP’s narrow band spectrum is an advantage, resulting in low spectral crosstalk. The major challenge for QWIP is developing broadband or multicolor optical coupling structures that permit efficient absorption of all required spectral bands.

中波高重频激光干扰非线性响应现象试验研究

针对中波探测器被中波高重频激光干扰时出现的非线性问题,设计了中波高重频激光器干扰制冷型中波HgCdTe焦平面探测器的干扰试验,分析了干扰出现的非线性响应输出现象,并得到了中波HgCdTe焦平面探测器干扰出现非线性响应时的阈值。

InGaAs单光子雪崩焦平面研究进展(特邀)

雪崩光电二极管(APD)是一种高灵敏度光电器件。按照工作电压的不同可分为线性APD和盖革APD。其中,盖革APD的工作电压高于击穿电压,利用半导体材料内部载流子的高雪崩增益可实现单光子级信号探测,也被称为单光子雪崩光电二极管(SPAD)。InGaAs材料SPAD在0.9~1.7μm光谱范围内有高量子效率,是1.06、1.55μm主动激光探测的理想探测器。通过将高效率InGaAs SPAD阵列芯片与CMOS计时/计数读出电路芯片集成封装,制备的雪崩焦平面探测器可对光子信号进行时间量化,在三维激光雷达、远距离激光通信、稀疏光子探测等领域有广泛应用。介绍了InGaAs单光子雪崩焦平面的器件结构及基本原理,在此基础上回顾了国内外雪崩焦平面技术的研究进展,并对未来发展方向进行了展望。

一种锥形自调式J-T制冷器

介绍了一种既可以实现快速启动又能够维持长时间小流量工作的锥形自调式J-T制冷器,可以广泛应用于制导导弹中红外焦平面探测器组件的制冷。该J-T制冷器采用微型波纹管作为自调机构,具有成本低、适应范围广等特点。与探测器杜瓦组件进行耦合试验,结果表明在50 MPa氩气气源条件下,芯片降温至100 K所需时间≤5 s。

锑化铟红外探测器的微透镜阵列设计及试验

台面型锑化铟红外焦平面探测器的制作工艺简单,量子效率高,但是填充因子较低且会随着像元尺寸的减小而进一步降低。减小台面腐蚀深度可以提高探测器的填充因子,但会增大串音。介绍了一种新型微透镜阵列的设计与制备方法,以提高锑化铟红外探测器的填充因子并减小串音。与现有的热回流微透镜阵列相比,该微透镜阵列的填充率、表面粗糙度以及尺寸均匀性能得到了较好的兼顾,可直接在锑化铟红外探测器表面制作,工艺简单。结果显示,探测器的串音降低26%,光响应提高22%。

超长线列红外探测器组件的低温面形研究

随着红外焦平面探测器阵列规模的不断扩大,由多层结构低温热失配形变导致的杜瓦可靠性问题愈发突出,对焦面低温形变的定量化表征需求越来越迫切。基于超长线列红外焦平面探测器冷箱组件开展焦面低温形变研究,针对多层结构粘接造成的焦面低温形变进行了理论仿真。设计了一种探测器工作温度90 K下焦面低温形变的测试方法。对比分析面形测试结果与仿真计算,低温下焦面整体下移,但变形曲线呈拱形。仿真得出两边芯片向下凹约9.24μm,中间位置芯片向下凹1.36μm。实验得出两边芯片向下凹约40μm,中间位置芯片向下凹10μm。数据差异与仿真材料的参数设置有关。验证了仿真结果的合理性,可为超长线列探测器焦面多层结构设计提供参考依据。

大电荷处理能力红外探测器读出电路像素设计

读出电路将红外探测器二极管激发产生的光电子收集、积分成为电压信号并按序读出,使其变成后端系统可读的电信号,是红外焦平面探测器的重要组成部分。电荷处理能力作为衡量读出电路的一项重要指标,探测器的性能以及某些应用条件下要求读出电路具有大的电荷处理能力,本文介绍一种具备大电荷处理能力的模拟读出电路像素级设计,在15μm像元间距内最大积分电容达到832 fF,最大电荷处理能达到10.92 Me^(-),且具备良好的线性度。

大视场激光探测与告警技术

利用四路红外非制冷焦平面探测器、大视场光学系统、窄带滤光片和信号处理系统,构成了凝视成像激光探测与告警系统.光学系统采用三片式结构的广角镜头来实现大视场;使用先进的非球面光学设计技术,并以FPGA完成探测器响应信号的非均匀校正,以改善像质;通过光学系统的畸变校正,提高激光的探测方向精度;利用激光和背景强度之间的反差,通过激光目标检测算法进行告警.实验表明,该系统能在127°视场范围内对波长为1.315μm, 2.7μm, 3.8μm, 10.6μm的4种激光进行告警,探测功率密度范围为0.05～50mW/cm2,探测方向精度可达1°.

红外成像制导技术发展现状与展望

随着信号处理、半导体技术的飞速发展,近几年红外成像制导技术取得了长足的进展。为了对该领域相关技术进行总结,为未来的研究工作提供参考,首先介绍了红外成像制导技术的概念,分析了红外光学系统、红外焦平面探测器以及图像处理等红外成像制导中的关键技术的发展现状。参考国内外红外成像制导领域的发展趋势,结合作者多年从事可见光、红外成像制导技术研究积累的经验以及对该领域关键技术的理解,预测了未来红外成像制导技术的发展方向。

平板探测器-实质血容量检测评价颈动脉内膜剥脱术围术期脑组织血流灌注

目的 总结分析平板探测器（FPD）-实质血容量（PBV）检测技术在颈动脉内膜剥脱术（CEA）患者围术期脑组织灌注评价中应用的可行性及临床价值。方法 连续收治的40例明确诊断为单侧症状性颈内动脉重度狭窄（70%～99%）患者均经复合手术室头颈部经颅多普勒超声和（或）全脑DSA评估并接受CEA手术，术前、术后即刻作FPD？蛳 PBV检测，评估脑组织血流灌注变化。结果 FPD-PBV技术可很好地检测CEA围术期患者脑组织血流灌注。40例患者均为单侧症状性颈内动脉起始段重度狭窄（左侧18例，右侧22例），术前患侧脑血流灌注明显低于健侧（P＜0.05）。顺利完成CEA术后DSA显示颈内动脉再通良好，颅内分支血流恢复，患侧脑血流灌注较术前增加（P＜0.05），其中22例术后脑灌注改善，但仍低于健侧（＜10%）；15例高于健侧（＜5%）；3例与健侧相等。术后患侧和健侧脑灌注间差异无统计学意义（P＞0.05）。结论 FPD- PBV检测是一种可行的、有较高临床应用价值的成像技术，可用于半定量分析脑灌注变化，为围术期治疗决策和疗效评价提供更多有价值信息。