Cost-effective double-layer antireflection coatings in mid-wavelength infrared band

In this letter, design and preparation of cost-effective double-layer antireflection (AR) coatings in mid-wavelength infrared band is investigated. The method of vector graphics which is simple and visualized for coatings designs with only a few layers is applied to design narrow-band double-layer AR coatings with high performance and low cost for laser applications. The experiment result verifies the design very well with peak transmittance very close to the theoretical limit.