Study and fabrication of laser and infrared two-wavebands antireflection film

According to the requirement of a particular optical instrument, the substrate was sapphire and ZnS and YbF3were chosen as high index and low index materials respectively, Macleod and TFCalc software were used to design and optimize the film stack, the deposition technology chosen was electron beam vacuum depositing method with the aid of ion assistance. An antireflection coating required with a transmittance at 1064nm wavelength of greater than 97% and the average transmittance over 95% in 3 ~ 5μm wavebands was achieved in practice. An inner barrier layer (M1) was added to improve the laser induced damage threshold (LIDT) of the AR coatings. The film meets the requirements of the optical instrument.