Formation of antireflection microstructures on the surfaces of diamond plates by the laser patterning method

A method for producing diamond plates, antireflective in the IR range, was proposed and implemented experimentally. This method involves formation, on the plate surfaces, of a regular relief structure with a period less than the radiation wavelength. The diamond surfaces were microstructured either by patterning with a focused Nd : YAP laser beam (λ = 1078 nm) or by scanning the image of a pattern in a projection system with the aid of an excimer KrF laser (λ = 248 nm). The shortest period of the resultant structures, consisting of a system of grooves or craters, was 3 μm. A study was made of the influence of the depth of the resultant structures on the transmission coefficient of a diamond plate. An increase in the transmission at the 10.6 μm wavelength amounted to 10% for a plate treated on both sides and the antireflection effect was then observed in a wide spectral range (10 — 20 μm).