Process-aware wideband near-infrared antireflection coating on K8 glass for shared front-end optoelectronic interfaces

A process-aware wideband near-infrared (NIR) antireflection coating (ARC) on K8 glass is developed for protected shared front-end optoelectronic interfaces operating near 800, 1064, and 1540 nm. Transfer-matrix simulations with anchored wavelength-dependent optical constants yield a nominal band-averaged reflectance, R avg , of 0.81% over 750–1600 nm. A bounded reconstruction of the fabricated stack, constrained by the ±7% optical-thickness control limit, yields R avg =0.74%, while the archival Photon RT experimental spectrum gives R avg =0.37% across the 750–1600 nm band, compared with approximately 4.3% for the bare K8 front surface. Angular calculations show R avg <1% up to 30° incidence. Preliminary tape-adhesion and ethanol-immersion screening demonstrate no visible macroscopic failure, supporting its potential use as a protected interface at normal-to-moderate incidence.