Fabrication and characterization of diamond moth eye antireflective surfaces on Ge

Abstract

An antireflective coating on Ge which combines a polycrystalline diamond film with a surface relief (moth eye) structure has been designed and successfully fabricated. This progressive gradation in the effective refractive index between air and the substrate has reduced Fresnel reflection losses to below 1%. This provides a means of overcoming the high refractive index and surface roughness considerations that often limit optical application of polycrystalline diamond thin films.