Fluorogallate glass is an infrared window material with good performance. In order to improve the window observation, detection and protection performance, three-band(0.4--0.9 m, 1.064 m and 3.7--4.8 m)composite anti-reflection protective films are designed and prepared on the fluorogallate substrate. According to the requirements of optical performance and environmental stability, the thin-film materials are selected and the membrane system is designed, and then the multilayer film is prepared by the electron beam evaporation method. The measurement results show that the water absorption peak at 2.9 m lowers the transmittance in the mid-infrared waveband. The film density is improved by improving the process and post-treatment and other ways, and the water absorption of the film layer is effectively suppressed. The environmental stability of the coated components is verified by the boiling-water immersion method. The results show that the thin-film samples processed by ion-assisted deposition and annealing have better optical properties and environmental adaptability.

A blind element analysis method for indium antimonide(InSb)infrared focal plane devices is proposed. By using this method, blind element testing and analysis can be performed without thinning the back of the device. Based on this packaging method, after the device is inverted, the radiation of light is absorbed from the front side of the chip, and testing and analysis can be performed after interconnection, glue filling, and each grinding and polishing process step. The results show that this method can effectively analyze and locate the blind elements generated during each step, and can solve the problem that the pixel failure in the infrared focal plane device due to the generated blind elements can not be located accurately in a certain process for the existing technical means.

The problem of signal layering often occurs in Dewar testing of InSb infrared focal plane arrays (IRFPA)detector, affecting the yield of device manufacturing. The cause of the detector signal layering was found by testing the level graph of the Dewar, I--V curve and the substrate doping concentration.Further theoretical analysis also shows that local high-concentration doped regions on the indium antimonide substrate will affect device performance. Based on this research, we can take corresponding measures during the preparation of the chip to minimize the ineffective work in the subsequent processes and improve the tape-out efficiency of the indium antimonide focal plane device process line.

Infrared imaging systems have been used in the military and civilian fields for many years, but have not been widely used, mainly due to their low resolution, high cost, unstable process and high technical threshold. Solving these problems requires improvements in sensor technology, detector packaging and infrared image processing chips. Infrared technology will develop in the future in the direction of low cost, dedicated processing chips and high resolution. At present, domestic manufacturers have successively launched new products such as wafer-level packaging, high-resolution detectors and dedicated image processing chips. However, there is no corresponding research on the infrared imaging system of these new devices. This article is mainly based on the practical application of Yantai IRay Technology Co., Ltd.′s new wafer-level packaged 1280×1024 infrared detector and the special image processing chip. The infrared imaging system is verified and analyzed in terms of system architecture, structural cooling and imaging algorithms.

Thermal time constant is a key parameter of the microbolometer, which constrains the maximum frame frequency of uncooled infrared detector. The pixel-level test of thermal response time can truly reflect the physical thermal response time of the sensor, and provide timely and effective data support for product design optimization. It is very important to accurately measure this parameter. However, the current pixel-level test methods have not been able to effectively compensate the self-heating effect of microbolometers, and can not accurately measure the thermal response time. The effective thermal response time of the microbolometer is measured based on the frequency response method. The self-heating effect is compensated by the resistance temperature coefficient, and the physical thermal response time can be accurately measured. The physical thermal response time measured under different bias currents is experimentally analyzed. The results show that this method has high accuracy and strong stability.

The light scattering model of the particles is the theoretical basis for calculating the extinction performance of the smokescreen materials, and it is also the key to study the interaction principle between the materials and the electromagnetic waves, and to design the advanced photoelectric interference materials theoretically. Several numerical calculation methods widely used in the field of the smokescreen materials calculation are introduced in detail, including T-matrix method, finite difference time domain(FDTD)method, finite element method (FEM) and discrete dipole approximation (DDA) method. The development process, the advantages and disadvantages, and the application status of these methods are described. The development direction of the extinction calculation and simulation of smokescreen particles is pointed out.

Under the sea-sky background, sea-sky-line detection can play an important role in detecting and tracking the ship targets. A method of sea-sky-line detection based on the analysis of the grayscale threshold is proposed. By analyzing the image and adjusting the step size of the linear filter, the gradient difference of the grayscale near the sea-sky-line is enlarged. The method based on threshold analysis is used to extract the edge coordinates, and the sea-sky-line is fitted through the least square method. The simulation verification is conducted by MATLAB as well. The results show that the proposed algorithm can accurately extract the sea-sky-line in the complex background, and has good adaptability and practicability.

The terahertz time-domain spectrometer（THz--TDS）has a promising prospect in many fields such as spectroscopy, material characterization, security check and communication. Firstly, a stable fiber short pulse laser with a wavelength of 1560 nm and how to integrate the laser into the THz--TDS system are introduced.Then the THz--TDS system is used for nondestructive testing of several kinds of ceramic matrix composites(CMC).Especially the thickness accuracy of the thermal barrier coating reaches m level.Compared with the traditional methods, the terahertz wave provides a better solution because it has stronger penetration to CMC and can be applied flexibly.Finally, the high-resolution spectral analysis of low-pressure water vapor is accomplished based on the terahertz asynchronous optical sampling(THz--ASOPS).The spectral resolution reaches 10MHz, which is more than 100 times higher than the traditional THz--TDS.