The purpose of this research is to develop broadband antireflection (A/R) coating for a high power acousto-optic modulator with the following specifications : the substrate material is TeO2 and the requirement of T (transmittance) for both sides greater than 98% in the spectral region 410-700 nm with laser power damage threshold is greater than 40 W/mm(2). The technology of A/R coating is based on the conventional method of nonreactive evaporation from electron beam gun sources oxides of Zr (ZrO2 films as a layer with high refractive index) and Si (SiO2 films as a layer with low refractive index), and YF3 (yttrium fluoride) films on TeO2 crystals substrate with pre-cleaning by using an ion beam gun (Refs. 1 and 5). The refractive indices of the mentioned films are : n(ZrO (2)) = 1.96-1.98, n(SiO2) = 1.45-1.46, and n(YF3) = 1.48-1.50 (Ref. 2). In all cases properties of A/R coating are strongly dependent on the method of surface cleaning, type of polishing, and even the bulk properties of the substrate.