Gradient optical film taking the place of classical high-reflectivity film

The feasibility of gradient optical films taking the place of classical layered structure high-reflectivity films in the field of high power laser is theoretically studied. To study the wavelength matching and electric field distribution, an example that the laser of 1 064 nm wavelength transmits in gradient optical films which is prepared with linear co-evaporation method is given. A numerical method which is applied to the gradient film with 14 perioded structure is proposed to obtain the matching thickness. Based on the Maxwell equation, the distribution of electric field is calculated. The result indicates that the distribution is similar to the classical layered high-reflectivity film but gradient film is likely to get damaged in surface. The design object of gradient film is to make