From the type point of view, PbSe belongs to narrow gap direct band gap semiconductor materials At room temperature, its detection performance is similar to that of cooled photonic infrared detection materials However, at present, there are still technical bottlenecks in the two standard manufacturing processes of PbSe detectors, and it is difficult to prepare large-area, high-performance PbSe photosensitive films. Therefore large array, high-performance PbSe infrared imaging systems have not been commercialized. In addition, the sensitization mechanism and photoelectric detection mechanism that induce and improve the infrared detection ability of PbSe thin films are still unclear, and the accurate and quantified guidance for the sensitization process of wafer-level PbSe thin films cannot be provided. This restricts the further optimization and improvement of the performance of the PbSe infrared detector. Based on the development history of PbSe infrared detector, the research results of device structure, preparation technology and detection mechanism of PbSe infrared detector are summarized, and the future development trend of PbSe infrared detector is predicted.

Based on the demand of working environments below liquid nitrogen temperature for very long wave infrared detectors, a kind of packaging technology for very long wave infrared detectors working at deep low temperature is proposed. Through innovative optimization design of the heat leakage and the chip electrical lead structure of the dewar, the static thermal load of the entire dewar can be controlled to be 0.65 W when the chip operates at a low temperature of 30 K, and the static thermal load at the coldest end position is 0. 3 W.The cooling capacity of the two-stage pulse tube refrigerator that is compatible with the dewar can meet the above thermal load requirements. The packaging test of the detector component is completed. The results show that under the air cooling test condition of the refrigerator expander's hot end, the detector chip can reach the temperature of 35 K, and the outer contour of the dewar is smaller than $130 mmX 180 mm. This technological achievement has promoted the progress of packaging technology for very long wave array infrared detectors operating at deep low temperature.

The important application significance of infrared polarization detectors for detecting and recognizing infrared camouflage targets and infrared dim targets is analyzed. The infrared polarization characteristics of objects and their representing methods are introduced in detail and the influencing factors of infrared polarization characteristics are expounded. Finally, the polarization fusion imaging algorithm is emphasized, which includes data preprocessing, infrared polarization fusion, and fusion image reprocessing. This artidle is of great significance for studying the fusion imaging of infrared polarization detectors

This research is devoted to optimizing PCB with simulation technology to improve its anti-electromagnetic interference ability. Based on the ANSYS SIWAVE simulation platform, we focus on identifying and solving problems that PCB may face in electromagnetic environments to improve system reliability and performance. First, the potential resonant frequencies and electromagnetic radiation points are identified through the modal analysis and frequency domain analysis of PCB. Then, the resonant frequency point is eliminated by adding decoupling capacitors The wiring scheme is adjusted, the signal transmission path is optimized, and the key signal lines are protected by simulation research on the high-speed signal aperture, which reduces the risk of signal distortion and timing problems. The simulation results show that these optimization measures have achieved remarkable results in improving PCB performance and stability.

The photoconductive antennas pumped by femtosecond laser pulses can generate broadband terahertz pulse radiation. A femtosecond laser pulse with a slowly rising-rapidly falling-shaped pulse envelope is used to interact with a photoconductive antenna to generate broadband terahertz radiation. The law of terahertz radiation is calculated based on the Drude-Lorentz model The influence of laser pulse duration and semiconductor carrier lifetime on terahertz radiation is discussed. The research results indicate that although the energy of this shaped femtosecond laser pulse is lost, this pumping method can generate wider terahertz radiation than normal femtosecond laser pulse-pumped photoconductive antennas. This result provides a new approach for generating broadband terahertz pulse radiation based on photoconductive antennas in experiments.

Due to the spectrum width of stimulated Brillouin gain, the best available spectral resolution is limited for the developed precision spectral analyzer based on the optical fiber stimulated Brillouin effect. In addition, the stimulated Brillouin gain coefficient is related to the power. These factors affect the performance of the NIR fiber Brillouin spectrometer. To solve these problems, the research is conducted and a spectral resolution enhancement method is proposed. In this method, two stages of stimulated Brillouin process are cascaded, combined with the power regulation of the measured light and the pump light, so that the stimulated Brillouin process is in the small signal linear high gain region. The results show that this method can achieve about 1.4 times spectral resolution enhancement. The spectral resolution enhancement method proposed in this paper breaks through the theoretical limitations and improves the performance of NIR fiber Brillouin spectrometer.