An anti-reflection coating for an infrared transmitting material and laser beam transmitting window or fiber incorporating the same

摘要

An anti-reflection coating for an infrared transmitting material, which is stable to water or moisture and free from deterioration of the performances for a long period of time, can be provided. This anti-reflection coating comprises an inner layer of an alkali metal halide and an outer layer, provided thereon, of an infrared transmitting material, the inner layer and outer layer being provided on a substrate of an infrared transmitting material and having refractive indexes in the range of shaded portion in FIG. 2, said refractive indexes of the inner and outer layer being based upon the refractive index n of the infrared transmitting substrate.