Anti-reflection coatings.

摘要

Optical devices, e.g. amplifiers, include anti-reflection coatings of hafnium oxide. The coatings are obtained by low temperature deposition in the presence of oxygen. It is important to adjust the degree of oxidation in order to obtain the target refractive index. Slower rates of deposition and oxidation favour stability of performance parameters. The coatings are useful for application to GaInAsP semiconductors.