Study And Fabrication Of Visible And Ir Dual-Band AR Coating

In order to meet the military instruments' operating requirements, we deposit AR coating on the substrate of ZnS at 400～1000nm(visible and near infrared band) and 7～11μm(far infrared band), it requires a average transmittance over 90%. We adopt electronic beaming vacuum depositing method with the aid of ion assistant deposition systems as well as chose ZnS as the material of high refractive index and YbF₃ as the material of low refractive index. Using three modular processing systems of the latest OptiLayer software as assistance, optimizing technical parameters, and improving monitor method, reducing thickness error, we have deposited AR coating on the substrate of ZnS to achieve the requirements. The average transmittance exceeds 91% through 400nm-1000nm wavelength. Moreover, it makes the transmittance over 90% through 7～11μm wavelength. In addition, The film can resist harsh environment and completely meet the demands of military optical instruments.