Graded index broadband antireflection coating prepared by glancing angle deposition for a high-power laser system

This paper reports that SiO2 is selected to fabricate broadband antireflection (AR) coatings on fused silica substrate by using glancing angle deposition and physical vapour deposition. Through accurate control of the graded index of the SiO2 layer, transmittance of the graded broadband AR coating can achieve an average value of 98% across a spectral range of 300–1850 nm. Moreover, a laser-induced damage threshold measurement of the fabricated AR coating is performed by using a one-on-one protocol according to ISOH254–1, resulting in an average damage threshold of 17.2 J/cm2.