OPTICAL PARTS FOR CO2 LASER AND MANUFACTURE THEREOF

摘要

PURPOSE:To obtain parts. whose absorption in the vicinity of 10.6mum is very few, by performing AR coating on both surfaces of KCl substrate by As2S3 and PbF2, thereby making it possible to use the KCl substrate as an evaporating substrate under the state deliquescence is prevented. CONSTITUTION:AR coating is performed on both surfaces of a KCl substrate 10 by using As2S3 (nd=2.49mum+ or -5%) 11a and 11b, PbF2 (nd=1.3mum+ or -5%) 12a and 12b and As2S3 (nd=1.0mum+ or -5%) under the conditions that the refractive indexes of the film at, e.g., 10.6mum are as follows: n=2.15 for As2S3 and n=1.55 for PbF2. The optical parts for CO2 laser described above are manufactured as follows: with the temperature of the KCl substrate 10 being kept at 60-100 deg.C, AR coating is sequentially performed on both surfaces of the KCl substrate 10 by using As2S3, PbF2 and As2S3.