Rutile (TiO2) large birefringence, large refractive index, is a method for spectral prism devices such as optical isolators and the polarization beam splitter and a very good material
Potassium tantalate (KTaO3, KT for short) single crystal has a stable cubic structure and can be used to make laser modulators, digital deflectors and semiconductor devices.
Yttrium doped zirconia needs to be added as stabilizer, with a common concentration of 13 mol%, YSZ has the characteristics of good mechanical and chemical stability and low cost
The lattice mismatch rate between lithium aluminate single crystal and gallium nitride is very small (1.4% for lithium aluminate), making it a high-quality substrate for gallium nitride thin films.