Activity: Talk or presentation types › Conference presentation
We present a novel anti-reflective coating from grass-like nanoporous Al2O3 with low refractive index and vertical index profile gradient. Fabrication of the coating includes atomic layer deposition of Al2O3 using thermal trimethylaluminium/water process and immersion of the deposited film in heated deionized water. Average optical transmittance in the range of 350--800 nm was 99.0% at normal incidence for double-side coated glass, the transmittance maximum of 99.5% was achieved at 500 nm. Transmittance spectra were also measured at different incident angles, average transmittance in the 350--800 nm range was 94.0% at 60 deg, 85.0% at 70 deg, and 53.1% at 80 deg incident angles, respectively. The grass-like Al2O3 ARC manufacturing technique is applicable to mass production, as ALD provides a possibility to coat hundreds of optical components at once. Additionally, unlike many other ARC deposition techniques used today (spin-coating, physical vapour deposition), grass-like Al2O3 fabrication is suitable for coating surfaces with extremely complex topography.