In this paper high-quality anti-reflective coatings of ZnSe-BaF2,ZnS-BaF2 and As2S3-BaF2 on Gallium Arsenide (GaAs) surface are described. They are characterized by an ability to withstand CW CO2 laser power up to 1000W/cm2 and a transmissivity of approximetly 98% at CO2 laser wavelength. The damage problem of the thin films on the sureface of windows, lenses etc. for a CW CO2 laser device has been solved and the output power of the device enhanced, thus creating condition for application and development of CO2 laser systems.