High performance ZnS antireflection sub-wavelength structures with HfO<sub>2</sub> protective film for infrared optical windows
Fei Liu, Hongfei Jiao, Jinlong Zhang, Bin Yin, Huasong Liu, Yiqin Ji, Zhanshan Wang, Xinbin Cheng
Abstract
Antireflection sub-wavelength structures (SWSs) on ZnS were designed and ZnS SWSs with HfO 2 protective film were prepared, and their properties in long-wave infrared applications were examined and compared to AR coatings. The SWS has good antireflection performance and exhibits less polarization sensitivity than the AR coating. At temperatures above 500 °C, the SWS with HfO 2 protective film has a better thermal endurance property than the multilayer AR coating. Moreover, the HfO 2 protective film significantly improved the mechanical properties of the ZnS SWS and was similar to HfO 2 covered AR coating when the HfO 2 film was not broken. This study shows that the ZnS SWS with HfO 2 protective film has promising application prospects in infrared optical windows.