Design of Three-Layer Antireflection Coating for High Reflection Index Lead Chalcogenide

Abstract

Antireflection coatings (ARC), not only reduce the reflection of the incident radiation but also protect the surface from environmental degradations. In present study, three-layer design was theoretically calculated and experimentally realized on the surface of lead chalcogenide, which had high refractive characteristics. First the theoretical designs of three-layers of different dielectric materials (i.e., ZnSe, SnO 2 , SiO and MgF 2) were simulated using optical matrix approach. Subsequently, the developed designs were experimentally produced on lead sulfide thin films using thermal evaporation technique. The efficiency of the designs was evaluated for 1500-2400 nm spectral range and found that the design comprising ZnSe-SiO-MgF 2 had 23% better performance than ZnSe-SnO 2-MgF 2 , besides consistent coating adhesion and morphology. The difference between theoretical and experimental results was less than 10 and 16 % for ZnSe-SiO-MgF 2 and ZnSe-SnO 2-MgF 2 , respectively.