With the development of terahertz technology, the research on terahertz transmission waveguide devices has also become one of the important issues to be solved. Terahertz wave is located between microwave and infrared light, and the search for efficient transmission and coupler devices has always been the goal of researchers This article mainly introduces the current research status of terahertz transmission waveguides and summarizes the advantages and disadvantages of various types of terahertz waveguides The research progress of metal waveguides and dielectric waveguides is analyzed according to material and structure Metal waveguides indude bare metal wire waveguides, microstructure waveguides, hollow core waveguides, and flat waveguides, while dielectric waveguides include dielectric hollow-core waveguides, porous core waveguides, and microstructure waveguides. Finally, prospects are presented for the future research directions that need to be addressed in terahertz transmission waveguides.

Silica (SiQ)) thin films have enormous potential for applications in semiconductor devices, integrated circuits, optical coatings, and other fields due to their excellent optical properties. However, the preparation process of SiO, thin films faces some issues such as surface roughness, impurity control, and compactness. Tò adress these issues, researchers have improved the performance of SiO, thin films through process improvements and surface modifications. Among the many techniques for preparing SiO, thin films, plasma enhanced chemical vapor deposition (PECVD) has become the most commonly used method for preparing SiO,thin films due to its advantages such as low temperature required for deposition and in-situ growth. This artide reviews the development of preparing SiO, thin films using PECVD technology, and explores the influence of key process parameters and post-treatment processes on the quality of the films The in-depth study of PECVD technology helps to achieve more precise control of SiO, film growth and further expand its broad application prospects.

Compared with short wave and medium wave devices, long wave infrared detectors have larger photocurrent and dark current, so they need strong charge storage capacity. However, the use of traditional analog pixel readout circuit technology is severely limited by charge storage ability, which makes it difficult to improve the dynamic range and signal-to-noise ratio of long-wave detector, restricting the development and application of long-wave infrared imaging system. In this paper, a pixel-level digital readout circuit technology is proposed, which overcomes the limitation of charge storage capacity of traditional analog integration scheme.The digital signal output of detector is realized. The dynamic range, anti-interference ability and frame rate of detector improve greatly. This technique is an effective way to improve the performance of long wave detector.Based on this technology, a digital readout circuit with 320X256 array and pixel spacing of 30 um is designed The output is transmitted by LVDS. The simulation results show that the maximum frame rate of the circuit can reach 1000 Hz, and the dynamic range is greater than 95 dR

The current blind element detection of infrared polarization detectors mainly relies on the discrimination method in GB/T 17444-2013, which ignores the statistical analysis of abnormal elements that cannot respond properly to polarized light. These elements cannot be eliminated by national standards, which seriously affects the imaging quality. Therefore, it is necessary to add a polarization blind element detection method on top of the original blind element detection method, so as to more accurately evaluate the blind element of polarization infrared detectors. A method for obtaining polarization blind elements through extinction ratio testing based on electric polarizers has been proposed, which can greatly reduce the testing error caused by internal polarization angle etching. At the same time, it can achieve multi-dimensional simultaneous detection of polarization blind elements of polarization devices, conventional overheated elements, and dead elements. Experimental verification is carried out using the 320X256 detector developed by our company. The number of blind elements identified using national standards is 1010. After introducing polarization blind elements, the number of blind elements is 1178; The overall number of blind elements increased by 0.2% compared to using the national standard discrimination method

As an important part of infrared detector assembly, split Stirling refrigerator has great influence on the performance of infrared detector assembly in practical application. Among them, the coupling gap between dewar and Stirling refrigerator is one of the most important factors affecting the performance of infrared detector. Therefore, the effect of the coupling gap on the performance of infrared detector is studied experimentally in this paper. When the chip temperature is 75 K and the cold head temperature of the refrigerator is 70 K, the deformation of the cold finger and dewar is simulated, and the coupling gap deformation is 0. 0096 mm.The low temperature environment has little influence on the deformation of the cold finger and dewar of the refrigerator, and the influence of the deformation of the cold finger and dewar on the coupling gap can be ignored. The experimental results show that the cooling time of the infrared detector module increases with the increase of the coupling gap. With the gradual increase of time, the corresponding DC currents of different coupling gaps are also different. At the same time, the smaller the coupling gap is, the smaller the DC current is. The diode voltage gradually increases and becomes stable with the increase of time. Before reaching the temperature control state, the smaller the coupling gap is at the same time, the larger the diode voltage is.

The aerodynamic optical effect is calculated and analyzed for the shape of THAAD-like infrared seeker, and it is used in aircraft design. Considering the thermochemical non-equilibrium effect and the coupling effect of material heat transfer, high-speed flow calculation software NNW-HyFLOW is used to simulate the flow field in typical state of the seeker. The flow field parameters such as density, temperature and pressure and the temperature field parameters of the window are obtained. Based on the flow field parameters, the infrared optical transmission imaging calculation is carried out by using the aero-optical transmission effect calculation function in HyFLOW. The thermal radiation calculation of flow field and optical window is carried out by using the aero-optical radiation effect calculation module. The calculation results show that when the THAAD-like seeker flies above 30 km, the flow field and optical window will not affect the optical transmission imaging of the target signal, but the thermal radiation effect of the flow field and window will affect the target recognition of the seeker. However, when the infrared seeker flies at a high altitude, the influence diminishes