Simultaneous enhancement of transmittance and haze for silica optical diffusers via moth-eye subwavelength structures

Silica optical diffusers (SODs) are widely utilized for their exceptional thermal and chemical stability, yet face persistent challenges in simultaneously enhancing their transmittance and haze. In this work, we successfully manipulate interfacial transmission and scattering (including geometric scattering and forward scattering) by fabricating parabola-shaped moth-eye subwavelength structures (SWSs). The moth-eye SWSs with controllable dimensions are fabricated on both flat surfaces of fused silica substrates and uneven surfaces of SODs through a dewetting-assisted plasma etching method. The peak transmittance wavelength positions in the 300-1100 nm range can be flexibly tuned by manipulating the dimensions of the moth-eye SWSs, achieving a maximum transmittance of 99.80% on flat substrates. Furthermore, the transmittance and haze of SODs are simultaneously improved through optimizing the transmission and scattering effects. The maximum improvements in transmittance and haze are 17.42% and 23.64%, respectively. We believe that this work can provide a solution with broadband response, wide-angle response, and excellent compatibility for high-end optoelectronic devices.