There are many types of materials used to manufacture optical products, including glass and plastic, and different materials are suitable for different devices or occasions. There are also many types of glass materials, some are harder and some are softer. Some are made of K9 material, some are made of quartz material, and some are made of sapphire or other materials. Here we will introduce the optical properties of sapphire window panels, including refractive index, dispersion, birefringence, etc.

1. Refractive index

The refractive index refers to the degree to which light is deflected when entering another medium from one medium. The refractive index is influenced by the wavelength of light, the composition, density, temperature, and pressure of the medium. The refractive index of sapphire window panels ranges from 1.760 to 1.778, which can be measured through experiments or instrument testing.

2. Disperse

Dispersion refers to the phenomenon where different colors of light refract at different angles when passing through, causing white light to decompose into a colored spectrum. Due to the different wavelengths of light of different colors, light undergoes varying degrees of refraction when passing through a medium, resulting in dispersion. The dispersion ratio of sapphire is between 0.018 and 0.019.

3. Birefringence

Birefringence refers to the phenomenon in certain crystals where the refractive index splits under the influence of the direction and wavelength of light propagation, resulting in two beams of light. This usually occurs in single crystals with high symmetry, and for sapphire, it has a typical triangular crystal structure, so birefringence can also occur.

Sapphire window panels have high surface hardness and can only be scratched by some high-intensity substances. The transmittance range extends from ultraviolet to mid infrared wavelengths. This substrate has chemical inertness and is insoluble in water, ordinary acids or bases at temperatures up to about 1000 ° C. It has the characteristics of high temperature resistance, good thermal conductivity, high hardness, infrared transmission, and good chemical stability, and is widely used in many fields such as industry, national defense, and scientific research (such as high-temperature resistant infrared windows).