Research progress on optical property test technologies of infrared materials under high-temperature and dynamic conditions

With the development of infrared technologies in the fields such as hypersonic vehicles, infrared guidance, and space exploration, the evaluation of optical properties of infrared window materials under high-temperature service conditions has become increasingly important. Conventional testing methods are mainly applicable to low-temperature, narrow-band, and static conditions, and therefore can’t adequately reveal the high-temperature dynamic optical behavior of these materials. This paper systematically reviews the testing principles and methods for key optical parameters, including transmittance, refractive index, emissivity, and absorption coefficient, under high-temperature dynamic conditions. Particular attention is given to the application characteristics and applicable ranges of Fourier transform infrared spectroscopy, double-beam spectrophotometry, the V-prism method, the minimum deviation angle method, the Etalon method, and laser calorimetry. Recent research progress is summarized, and the advantages and limitations of different methods are compared in terms of testing accuracy, temperature range, and experimental conditions. Existing studies still face several challenges, including the lack of unified standards for high-temperature dynamic testing, insufficient availability of general-purpose testing equipment, limited testing temperature and spectral ranges, inadequate capability for simulating service environments, and insufficient research on antireflective protective films. In response to these issues, future development directions are proposed, including high-temperature dynamic continuous testing, multi-band broadband testing, high-temperature optical performance testing of antireflective protective films, and testing under simulated service environments.