红外探测器组件杂散光分析及抑制研究

发布时间：2018-07-05 07:04

本文选题：红外探测器组件 + 杂光抑制　；参考：《中国科学院研究生院(上海技术物理研究所)》2016年博士论文

【摘要】：红外探测器组件的性能很容易受测试或工作环境中各种杂散光的影响,进一步影响到红外探测系统的成像质量。在红外探测系统中,红外探测器组件是目标探测和成像系统的核心器件,因此其杂散光的抑制相当重要。本文针对多波段红外探测器组件光学串音和焦平面杜瓦探测器组件的杂散光抑制,完善了一套红外小光点测试系统,并建立一套异形冷屏点源透过率(PST)测试系统。利用这两套测试系统,我们测试和分析了红外探测器组件的杂散光抑制效果,并针对性地提出了一些改进措施,研究结果对工程应用具有一定意义。本文首先对杂散光传播的基础理论和国内外研究动态进行简单介绍,杂散光在红外探测系统中的传播主要依赖三个因素:双向反射分布函数(BRDF)、几何构成因子(GCF)和入射辐射通量,因此对其抑制主要考虑从辐射背景抑制、结构设计改进,表面发黑处理三方面进行。目前探测器组件杂散光抑制效果评价的方式有杂散光软件建模模拟和杂散光参数实测两种。本文主要从搭建的杂散光测试系统中提取PST和光学串音等指标来评价红外探测器组件的杂散光抑制效果。接着对不同结构多波段红外探测器组件的光学串音进行测试和评价,并据此分析杂散光来源及改进措施。采用傅立叶响应光谱测试系统的测试了多波段红外探测器组件,根据测试结果对带外杂散光抑制进行了评价。为进一步研究杂散光在探测器组件内的空间分布,完善了红外小光点测试系统,主要解决了微弱信号采集、30μm细亮条的高精度对准和数据自动采集三个关键技术问题,实验验证表明系统的重复性优于96%和狭缝聚焦宽度约30μm。采用该套系统测试中短波、水汽和长波三种多波段探测器组件,获得了相应的光学串音评价结果,研究了不同结构长波探测器组件光学串音,明确叠层电极结构侧面的光吸收区是引起组件MTF偏小的原因,滤光片和光敏元间距越小越有利于探测器组件杂散光抑制。最后,研究了红外焦平面探测器组件杂散光抑制的测试和评价方法。采用光线追迹法替代复杂的公式计算异形冷屏效率,获得冷屏对焦平面探测器均匀性的影响。为了测试和评价异形冷屏结构对杂散光抑制效果,设计和搭建杜瓦冷屏PST测试系统,解决杜瓦冷屏PST测试系统光源在像面处辐射均匀性的问题,并采用该套系统测试不同结构冷屏的PST与视场角的关系曲线,与软件仿真结果能很好地符合,同时对冷屏结构设计提出了一些建设性意见。
[Abstract]:The performance of the infrared detector module is easily affected by the stray light in the test or working environment, which further affects the imaging quality of the infrared detection system. In infrared detection system, infrared detector module is the core device of target detection and imaging system, so the suppression of stray light is very important. Aiming at the stray light suppression of multi-band infrared detector module optical crosstalk and focal plane Dewar detector module, a set of infrared small light spot measurement system and a special cold screen point source transmittance (PST) measurement system are developed in this paper. Using these two test systems, we have tested and analyzed the stray light suppression effect of infrared detector module, and put forward some improvement measures. The research results have some significance for engineering application. In this paper, the basic theory of stray light propagation and the research trends at home and abroad are briefly introduced. The propagation of stray light in infrared detection system mainly depends on three factors: bidirectional reflectance distribution function (BRDF), geometric composition factor (GCF) and incident radiation flux. Therefore, the suppression is mainly considered from three aspects: radiation background suppression, structural improvement and surface blackening. At present, there are two methods to evaluate the effect of stray light suppression in detector modules: modeling and simulation of stray light software and measurement of stray light parameters. In this paper, PST and optical crosstalk were extracted from the stray light measurement system to evaluate the suppression effect of stray light of infrared detector module. Then the optical crosstalk of multi-band infrared detector modules with different structures is tested and evaluated, and the source of stray light and improvement measures are analyzed accordingly. The multi-band infrared detector module was tested by Fourier response spectroscopy. The suppression of out-of-band stray light was evaluated according to the test results. In order to further study the spatial distribution of stray light in the detector module, the infrared small spot measurement system is perfected, and three key technical problems of high precision alignment and automatic data acquisition of 30 渭 m thin bright strip for weak signal acquisition are mainly solved. The experimental results show that the repeatability of the system is better than 96% and the slit focusing width is about 30 渭 m. In this system, three kinds of multiband detector assemblies, short wave, water vapor and long wave, are tested. The corresponding optical crosstalk evaluation results are obtained, and the optical crosstalk of long wave detector modules with different structures is studied. It is clear that the light absorption region on the side of the laminated electrode structure is the cause of the smaller MTF, and the smaller the distance between the filter and the Guang Min element is, the better the stray light suppression of the detector module is. Finally, the test and evaluation method of stray light suppression for infrared focal plane detector module is studied. The light tracing method is used instead of the complicated formula to calculate the efficiency of the special cold screen and the effect of the cold screen on the uniformity of the focal plane detector is obtained. In order to test and evaluate the effect of abnormal cold screen structure on the suppression of stray light, the PST test system of Dewar cold screen is designed and built to solve the problem of radiation uniformity of the light source in the image plane of the Dewar cold screen PST test system. The curve of the relationship between PST and field of view angle of cold screen with different structures is tested by this system, which is in good agreement with the simulation results of software. Some constructive suggestions on the structure design of cold screen are put forward at the same time.
【学位授予单位】：中国科学院研究生院(上海技术物理研究所)
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN215

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