Design and optimization of anti-reflection coating with the structure of one-dimensional rectangular groove phase grating

A kind of anti-reflection (AR) coating with simple structure applicable in visible bands was designed. The characteristics of the AR-coatings were investigated by using the effective medium theory (EMT). The antireflective characteristics of 4 different substrate materials were compared and the polymethylmethacrylate (PMMA) was chosen for substrate to analyze the influences of the duty cycle, etching depth, incident wavelength and incident angle on the reflectivity of the groove phase grating. A set of parameters in the visible waveband of light are given. The research results show that the reflectivity is less than 2% in the waveband from 0.4 m to 0.55 m at the incident angle less than 30; the reflectivity is less than 2% in the waveband from 0.4 m to 0.8 m at the incident angle less than 10.