Optical crystal refers to those used in Crystal optical circuits. Mainly used in optical instruments, through Windows, prisms, lenses, filters and polarizing elements and the phase compensator, optical circuits are mainly used in the light emission, processing and receiving parts. Another noteworthy is the recent development of fiber optical crystal crystals and optical waveguide using crystals, important in optical circuits used in optical transmission, transformation, and branch.
It should be noted that in all these applications, mainly is occupied by glass and glass fiber. Optical crystal just beyond the edge of the glass or special occasions in order to find its place. Applications such as high-speed flyer when Windows or bulletproof Windows, and so on, would require the window material through the band width, high melting temperature, thermal conductivity and mechanical strength is high, glass is often not up to the requirements in these areas, so people on the selection of Crystal Al2O3. In addition, some of Crystal's refractive index and dispersion is much larger than the glass, resulting in some special applications, Crystal optical element smaller than the glass, better performance, and refractive index and dispersion is man-made gemstones required, so artificial Crystal in jewelry market significantly play a more important role than glass.