Abstract:Target detection technology based on infrared detection systems has been widely used in security, early warning, and other fields. However, due to the weak signal and small feature scale of infrared dim and small targets, problems such as missed detection, false detection, and false alarms are prone to occur in complex application scenarios. Significant progress has been made in infrared dim and small target detection based on traditional image processing methods and deep learning algorithms. This paper discusses the latest research progress in infrared dim and small target detection methods, covering single-frame detection methods, multi-frame detection methods, and deep learning methods. It analyzes the advantages and limitations of existing technologies and summarizes the future development direction of infrared dim and small target detection algorithms.

Abstract:Generative adversarial network (GAN), as a powerful deep learning model, has demonstrated significant potential and application prospects in the field of infrared image simulation in recent years. This paper first summarizes the development of infrared simulation technology both domestically and internationally. It then details the latest progress and main methods of GAN-based infrared image simulation research, which are mainly divided into two methods: infrared simulation using random noise and infrared simulation using visible light images. It also describes the quality evaluation methods and evaluation indicators of generated infrared images (mainly subjective and objective evaluation methods). Finally, the future development trends of GAN in the field of infrared simulation are prospected.

Abstract:A silicon-based HgCdTe p-on-n heterojunction thin film material is reported, focusing on the structural design and growth of the multilayered material. Both n-type and p-type doping of the HgCdTe thin film is achieved using molecular beam epitaxy. The average macro-defect density on the surface of the obtained heterojunction material is approximately 500 cm^-2. Secondary ion mass spectrometer results indicate that both the n-type and p-type layers of the heterojunction material achieved the ideal doping concentrations of 1.02×10¹⁵ cm^-3 and 5.15×10¹⁷ cm^-3, respectively. A mid-wave infrared focal plane array fabricated based on this heterojunction material exhibits excellent optoelectronic performance, with a reverse bias voltage exceeding 800 mV.

Abstract:This paper introduces the importance of two-color infrared detectors for target identification, explains the operating principles of common two-color infrared detectors, and points out the limitations of spectral crosstalk test methods. Integrating the crucial role of response voltage in practical applications, the response-voltage crosstalk test method is demonstrated based on the principle of Planck blackbody radiation. Calculation results show that the spectral crosstalk from the long-wave band to the mid-wave band for the example two-layer two-color detector is 13.7%, while the response-voltage crosstalk from the long-wave band to the mid-wave band is 2.3%. Imaging verification shows that the crosstalk ratio from the long-wave band to the mid-wave band in actual application scenarios is approximately 2.4%, demonstrating the practicality of the response-voltage crosstalk test method. This method is applicable not only to two-layer two-color infrared detectors but also to single-layer spliced two-color infrared detectors, providing valuable insights into the development of two-color infrared detector chips.

Abstract:The composite substrate layer, a crucial buffer layer in Si-based HgCdTe materials, changes the epitaxial growth method of the ZnTe buffer layer within the composite substrate. The composite substrate is prepared by directly growing the ZnTe layer using a molecular beam epitaxy system. The substrate temperature is then adjusted to identify a process more suitable for direct epitaxy. Scanning electron microscopy (SEM), reflection high-energy electron diffractometer (RHEED), and white-light interferometry are used to investigate the effects of varying substrate temperature, buffer layer thickness, and epitaxial growth method on the material′s full width at half maximum (FWHM), phase deviation angle, roughness, RHEED patterns, and dislocation density. The results show that a thicker ZnTe buffer layer significantly reduces the dislocation density by an order of magnitude. By first growing a low-temperature seed layer and then epitaxially growing the ZnTe, the crystal orientation shift can be effectively reduced, resulting in even lower roughness.

Abstract:Aiming at the influence of errors on three-dimensional fiber Bragg grating (FBG) accelerometers used in precision measurement and long-term monitoring, an error analysis and consistency assessment method based on Allan variance is proposed. An error model for the FBG accelerometer is established, and the Allan variance noise characteristics along three orthogonal axes are analyzed. The consistency of the three-axis performance is evaluated, and possible causes of inconsistency are investigated. By varying the correlation time τ of the sample subsets in the Allan variance analysis, the characteristics of different random processes at different time scales are further investigated. Based on experimental results, an error analysis of the three-dimensional FBG accelerometer is conducted, and the main error sources are identified, providing an important theoretical basis for performance optimization and error compensation of this type of geophone.