高性能红外探测系统研究

发布时间：2018-01-13 20:04

本文关键词：高性能红外探测系统研究　出处：《上海交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：红外探测在物理、化学、医疗、军事等诸多领域有重要应用,高性能探测系统的研究对于推动该领域的发展具有重要意义,而探测器与探测系统的搭建是决定探测系统性能的关键因素。量子阱探测器凭借其较好的均匀性、成熟的工艺和高速的响应等优点在中红外及太赫兹波段探测中受到越来越广泛的关注。本文首先研究了影响及限制中红外、太赫兹量子阱探测器性能的因素。然后,针对弱信号探测,提出了一种基于光栅干涉仪的低背景探测系统。在探测器研究部分,本文对峰值波长为9微米的中红外量子阱探测器和峰值波长为44微米的太赫兹量子阱探测器进行了实验与理论的细致研究。对于中红外量子阱探测器,理论与实验相结合,系统的研究了暗电流的温度特性及偏压特性,研究了暗电流的主要机制,并给出了该器件的极限探测率。对于太赫兹量子阱探测器,系统的研究了其暗电流的温度特性,偏压特性,并对其热激发,散射辅助隧穿及阱间隧穿对暗电流的贡献进行了计算。同时,对其光电流响应进行了讨论。由于其结构特点,太赫兹量子阱探测器工作温度较低,极大限制其应用,对此提出两种提高其工作温度的方法。在探测系统部分,本文提出了可实现红外弱信号探测的高性能探测系统,该系统能有效降低探测器的背景辐射,进而提高探测器的探测率和信噪比。首先,分析了工作在不同状态下限制探测器性能的因素,结果表明暗电流限制模式下,降低器件工作温度即可提高探测性能,但一旦进入背景限制模式,则必须降低背景辐射才能继续提高探测性能,即要实现低背景探测。然后,针对红外应用中最常见的傅利叶红外光谱仪系统,分别介绍了迈克尔逊型和光栅型两种光谱仪结构,结果表明用传统迈克尔逊型光谱仪实现低背景探测需将整个干涉仪部分、光源及探测器都置于低温环境下,结构复杂;然而,对于光栅型光谱仪,只需将光源和探测器部分置于低温下即可实现低背景探测,简单易行。最后,对系统的性能进行计算,结果表明,理想情况下,对工作在背景限制下的探测器,当由300K的背景辐射降至77K时,其探测率和信噪比可提高二至三个数量级,对实际9微米量子阱探测器器件,峰值探测率可提升一个数量级,该设计对于红外高性能探测的实现具有重要意义。
[Abstract]:Infrared detection in the physical, chemical, medical, military and other fields have important applications, the research on high performance detection system is of great significance to promote the development of the field, and build the detector and the detection system is a key factor in deciding the detection performance of the system. Quantum well detector with good uniformity, more and more attention mature technology and high speed response advantages in infrared and terahertz detection. This paper studies the influence and restriction factors in infrared, terahertz quantum well detector. Then, aiming at the weak signal detection, and propose a low background detection system based on grating interferometer. In the detector research in this paper, the peak wavelength of terahertz quantum well photodetectors 9 micron infrared quantum well detector and the peak wavelength of 44 microns is studied by experiment and theory of fine For mid infrared quantum well detector, the combination of theory and practice, systematically studied the temperature characteristics and bias characteristics of dark current, the main mechanism of the dark current, and gives the limit of the device detection rate. For THz quantum well detector, the system of the dark current temperature characteristic, bias and, on the thermal excitation, scattering assisted tunneling and tunneling between traps on the dark current contribution is calculated. At the same time, the photocurrent response is discussed. Because of its structural features, THz quantum well detector working temperature is low, which limits its application, puts forward two kinds of methods to improve the working temperature the detection system. In the part, is proposed in this paper can achieve high performance infrared detection system of weak signal detection, the system can effectively reduce the background radiation detector, and then improve the detection rate of the probe and signal to noise ratio. First, analyzes the factors limiting the performance of the detector working under different conditions. The results show that the dark current limiting mode, reducing device temperature can improve the detection performance, but once in the background of limited mode, we must reduce the background radiation in order to improve the detection performance, namely to achieve low background detection. Then, according to the most common infrared application the Fourier transform infrared spectrometer system, the paper introduces the Michelson type and type two grating spectrometer structure, the results show that the traditional Michelson spectrometer to achieve low background detection should be the interferometer, the light source and detector are placed in the low temperature environment, complex structure; however, the grating spectrometer, only the light source under low temperature and the detector can achieve low background detection, simple and easy. Finally, the performance of the system was calculated, the results show that under ideal conditions, To work in the background under the limit of the detector, when the background radiation of 300K to 77K, the detection rate and the SNR is increased by two to three orders of magnitude of the actual 9 micron quantum well detector device, the peak detection rate can be improved by an order of magnitude, the design has important significance to the realization of high performance infrared detection.

【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN215

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