Sapphire lenses, as excellent optical lenses, have good transmittance in the ultraviolet, infrared, and visible light bands, and can meet the requirements of multi-mode composite guidance. At the same time, sapphire filters have excellent mechanical properties, chemical stability, good high temperature resistance, high strength, high hardness, and can meet the strict requirements of hypersonic transmission plates.

The performance requirements for infrared transparent windows are high strength and the ability to withstand decompression loads during high-speed motion. In terms of thermal stability, it should be able to withstand the temperature effects caused by aerodynamic heating and height changes, and the transmittance and refractive index should not change significantly with temperature changes. Sapphire lenses are made at high temperatures and are a hard material with a working temperature of up to 1900 degrees Celsius.

Sapphire is an ideal multispectral broadband window material, which has many excellent mechanical and optical properties compared to ordinary broadband window materials, and is suitable for laser instruments, optoelectronic devices, window materials, etc. SiO2 thin films were prepared on sapphire substrates using sputtering method, and the infrared transmittance of sapphire samples before and after coating, as well as the infrared transmittance after coating, were tested. The uncoated sapphire samples after high temperature and rain erosion were tested and analyzed. The average transmittance qualification rate of the coated sapphire samples was very low, and the infrared transmittance of the coated sapphire was significantly higher than that of the uncoated sapphire.

In terms of preparation, sapphire lenses can be used to produce optical filters, which can then be processed and shaped into finished products with the same performance as optical filters. Other boards are mainly made by powder hot pressing sintering, and their performance is not as good as sapphire. Sapphire filters have been applied in biomedical, optical information processing, consumer electronics, and other fields.