Optical single crystal type
Halide single crystal
The halide single crystal is classified into a fluoride single crystal, a compound single crystal of bromine, chlorine, and iodine, and a halide single crystal of ruthenium. Fluoride single crystals have high transmittance, low refractive index and low light reflection coefficient in the ultraviolet, visible and infrared spectral regions; the disadvantages are large expansion coefficient, small thermal conductivity and poor impact resistance. Compounds of bromine, chlorine and iodine can pass through a wide infrared band, and have a low melting point, which is easy to produce a large-sized single crystal; the disadvantages are easy deliquescence, low hardness and poor mechanical properties. Bismuth halide single crystal also has a wide infrared spectrum transmission band, slightly soluble in water, is a detector window and lens material used at lower temperatures; the disadvantage is cold rheology, susceptible to hot corrosion, It is toxic.
Oxide single crystal
The oxide single crystals mainly include sapphire (Al 2 O 3 ), crystal (SiO 2 ), magnesium oxide (MgO), and rutile (TiO 2 ). Compared with the halide single crystal, it has a high melting point, good chemical stability, and good permeation performance in the visible and near-infrared spectral regions. Used to fabricate a variety of optical components from the ultraviolet to infrared spectral region.
Semiconductor single crystal
The semiconductor single crystal has a single crystal (such as a germanium single crystal, a silicon single crystal), a II-VI semiconductor single crystal, a III-V semiconductor single crystal, and diamond. Diamond is the longest crystal in the spectrum, extending to the far infrared region, with high melting point, high hardness, excellent physical properties and chemical stability. Semiconductor single crystals can be used as infrared window materials, infrared filters, and other optical components.