Bioinspired ZnS Infrared Detection Window with Enhanced Broadband Transmittance via Green Picosecond Laser Assisted with Chemical Etching

Abstract

Due to the complex parameters of antireflective subwavelength structures (ASS) and the limitations of Gaussian beam manufacturing, fabricating ASS with ultrahigh transmittance directly on ZnS infrared window materials using ultrafast laser remains a significant challenge. Here, we propose a method for designing, manufacturing, and characterizing an ultrahigh-performance broadband infrared window utilizing a green picosecond Bessel beam assisted with chemical etching. Then, inspired by the excellent antireflective properties of the special structure of cicada’s wings, two types of ASS arrays with six diverse periods are successfully fabricated by shaping a Bessel beam accompany with 5% HNO₃ acid etching. It is demonstrated that the average transmittance of the above six samples increased by 4.67% to 8.96% in the wavelength of 5∼12 μm, with a notable increase of 5.68% to 12.15% in the far-infrared range of 8∼12 μm, peaking at 13.14% at 9.26 μm. The remarkable performance and broadband infrared window produced by this method demonstrate great potential in an optoelectronic device application that can operate effectively under extremely harsh conditions.