Large-area patterning for broadband, quasi-omnidirectional low-reflectance glass

A method for producing large-area, broadband, quasi-omnidirectional low-reflectivity glass surfaces is presented. Using block copolymer patterning and inductively coupled plasma etching, near-periodic arrays of pillars are formed in glass. The patterned surface has reflectivity $\lt$0.5%—almost an order of magnitude smaller than plain glass—with a bandwidth of ∼300 nm. Substrates etched on both sides transmit $\gt$99.5% across the wavelength range 850–1200 nm, with $\gt$99% down to λ = 650 nm. The process is demonstrated on a 5 cm diameter fused silica wafer and high transmittance is maintained up to at least 70∘ incidence. The resulting substrates might find application as lab optics (windows, lenses, etc) display screens for televisions, computers, phones, and as encapsulants for optoelectronic devices.