ZnSe is a kind of yellow and transparent mulit-cystal material, the size of crystalline particle is about 70um, transmitting range from 0.6-21um is an excellent choice for a variety of IR applications including high power CO2 laser systems.
ZnS is a very important optical crystals applied in IR waveband. Transmitting range of CVD ZnS is 8um-14um, high transmittance, low absorption, ZnS with multi-spectrum level by heating etc. static pressure technics has improved the transmittance of IR and visible range.
Calcium Fluoride has widespread IR application as spectroscopic CaF2 windows, CaF2 prisms and CaF2 lenses. Especially pure grades of Calcium Fluoride (CaF2) find useful application in the UV and as UV Excimer laser windows. Calcium Fluoride (CaF2) is available doped with Europium as a gamma-ray scintillator and is harder than Barium Fluoride.
Silicon is a mono crystal primarily used in semi-conductor and is non-absorptive at 1.2μm to 6μm IR regions. It is used here as an optical component for IR region applications.
The Germanium as a mono crystal primarily used in semi-conductor is non-absorptive at 2μm to 20μm IR regions. It is used here as an optical component for IR region applications.