基于五轴转台红外目标/干扰模拟器的实施方案

基于五轴转台的红外制导武器半实物仿真系统,以目标 /干扰环境成像质量好、光能利用率高、目标视线误差小为特色,是红外半实物仿真领域的佳作。而基于五轴转台红外目标 /干扰模拟器的轻质量和抗震动、抗冲击性能,是其中的关键。本文介绍了基于五轴转台红外目标 /干扰模拟器的实施方案, 系统设计过程中为减轻其质量采取的一系列重要的措施,以及系统误差源的分析和误差的分配原则。     

Inductively coupled plasma etching for large format HgCdTe focal plane array fabrication

Inductively coupled plasma (ICP) using hydrogen-based gas chemistry has been developed to meet requirements for deep HgCdTe mesa etching and shallow CdTe passivation etching in large format HgCdTe infrared focal plane array (FPA) fabrication. Large format 2048×2048, 20-μm unit-cell short wavelength infrared (SWIR) and 2560×512, 25-μm unit-cell midwavelength infrared (MWIR) double-layer heterojunction (DLHJ) p-on-n HgCdTe FPAs fabricated using ICP processing exhibit >99% pixel operability. The HgCdTe FPAs are grown by molecular beam epitaxy (MBE) on Si substrates with suitable buffer layers. Midwavelength infrared detectors fabricated from 4-in. MBE-grown HgCdTe/Si substrates using ICP for mesa delineation and CdTe passivation etching demonstrate measured spectral characteristics, RoA product, and quantum efficiency comparable to detectors fabricated using wet chemical processes. Mechanical samples prepared to examine physical characteristics of ICP reveal plasma with high energy and low ion angle distribution, which is necessary for fine definition, high-aspect ratio mesa etching with accurate replication of photolithographic mask dimensions.     

256×256 focal plane array midwavelength infrared camera based on InAs/GaSb short-period superlattices

An infrared camera based on a 256×256 focal plane array (FPA) for the second atmospheric window (3–5 μm) has been realized for the first time with InAs/GaSb short period superlattices (SLs). The SL detector structure with a broken gap type-II band alignment was grown by molecular beam epitaxy on GaSb substrates. Effective bandgap and strain in the superlattice were adjusted by varying the thickness of the InAs and GaSb layers and the controlled formation of InSb-like bonds at the interfaces. The FPAs were processed in a full wafer process using optical lithography, chemical-assisted ion beam etching, and conventional metallization technology. The FPAs were flip-chip bonded using indium solder bumps with a read-out integrated circuit and mounted into an integrated detector cooler assembly. The FPAs with a cut-off wavelength of 5.4 μm exhibit quantum efficiencies of 30% and detectivity values exceeding 10¹³ Jones at T=77 K. A noise equivalent temperature difference (NETD) of 11.1 mK was measured for an integration time of 5 ms using f/2 optics. The NETD scales inversely proportional to the square root of the integration time between 5 ms and 1 ms, revealing background limited performance. Excellent thermal images with low NETD values and a very good modulation transfer function demonstrate the high potential of this material system for the fabrication of future thermal imaging systems.     

Molecular beam epitaxy growth of high-quality HgCdTe LWIR layers on polished and repolished CdZnTe substrates

We report here molecular beam epitaxy (MBE) mercury cadmium telluride (HgCdTe) layers grown on polished and repolished substrates that showed state-of-the-art optical, structural, and electrical characteristics. Many polishing machines currently available do not take into account the soft semiconductor materials, CdZnTe (CZT) being one. Therefore, a polishing jig was custom designed and engineered to take in account certain physical parameters (pressure, substrate rotational frequency, drip rate of solution onto the polishing pad, and polishing pad rotational velocity). The control over these parameters increased the quality, uniformity, and the reproducibility of each polish. EPIR also investigated several bromine containing solutions used for polishing CZT. The concentration of bromine, as well as the mechanical parameters, was varied in order to determine the optimal conditions for polishing CZT.     

Modeling of the zero-bias resistance-area product of long wavelength infrared HgCdTe-on-Si diodes fabricated from molecular beam epitaxy-grown epitaxial layers

The electrical effects of dislocations has been studied by modeling zero-bias resistance-area product (R₀A) of long wavelength infrared diodes fabricated in molecular beam epitaxy (MBE)-grown HgCdTe-Si epitaxial films. Results show that dislocations influence both 40 K and 78 K R₀A products in high dislocation density (HgCdTe/Si) material. In low dislocation density samples (HgCdTe/CdZnTe), the variations in 78 K R₀A are limited by the composition (x) variations in Hg_1-xCd_xTe material, whereas dislocation contribution dominates the variations at 40 K. The origin of relatively large spread in 40 K R₀A in both types of samples is traced to the statistical variations in the core charges of dislocations. It is concluded that additional alternatives besides the reduction of dislocation density (such as control of core charges), may also need attention in order to make Si a viable substrate material for the growth of HgCdTe epitaxial layers suitable for devices operating at 40 K.     

弹用红外干扰发烟剂研制

对铜基红外干扰发烟剂的配方及影响配方性能的主要因素进行了实验研究，并对其性能进行了测试。结果表明，该发烟剂不仅对中、远红外光具有优良的干扰能力，而且对可见光、激光也具有良好的遮蔽能力。该发烟剂还具有装填密度大，不导电，耐高、低温性能、相容性和稳定性能良好等特点。     

MEALINESS DETECTION IN APPLES USING TIME RESOLVED REFLECTANCE SPECTROSCOPY

Mealiness is a textural attribute related to internal fruit disorder that is characterized by the combination of abnormal softness of the fruit and absence of free juiciness in the mouth when eaten by the consumer. Time‐resolved laser reflectance spectroscopy was used as a tool to determine mealiness. This new technique in agrofood research may provide physical and chemical information independently and simultaneously, which is relevant to characterize mealiness. Using visible and near infrared lasers as light sources, time‐resolved laser reflectance spectroscopy was applied to Golden Delicious and Cox apples (n = 90), to characterize batches of untreated samples and samples that were stored under conditions that promote the development of mealiness (20C & 95% RH). The collected database was clustered into different groups according to their instrumental test values. The optical coefficients were used as explanatory variables to build discriminant functions for mealiness. The performance of the classification models created ranged from 47 to 100% of correctly identified mealy versus nonmealy apples.     

红外混合光学系统传递函数的一种测试方法及实现

介绍了利用刀口扫描法测试红外混合光学系统光学传递函数的原理，采用此方法，设计了一套实用的红外混合透镜性能测试系统，可实现红外混合光学系统点扩散函数和光学传递函数的测量；针对3～5μm波段的红外混合光学系统进行了像质评价，给出了测试结果；此测试系统对红外混合光学系统的设计、加工以及像质评价具有实际意义。     

一种红外屏电路的驱动电流自适应调节方案

本文分析了现有红外触摸屏寿命较短的原因，提出了一种驱动电流自适应调节的红外触摸屏电路结构以及自适应调节方法，同时给出了坐标归一化计算方法。本文提出的方法能够根据接收信号的强弱对红外发光管驱动电流进行补偿，采用此项技术设计的红外触摸屏电路具有较强的抗干扰能力，其使用寿命也大大延长。     

新型回转窑筒体温度红外扫描计算机监测系统研究

介绍了新型回转窑筒体温度红外扫描计算机监测系统的组成、功能、特点及各种动态补偿算法。通过在长城铝业集团 4台回转窑上近一年的试运行 ,取得了令人满意的控制效果