Effect of wavelength on damage of optical materials with SBS

The transient stimulated Brillouin scattering (SBS) process was studied based on the coupled-wave theory. The time-varying distributions of the intensities of pump light, Stokes light and induced stress were obtained by solving the nonlinear coupled-wave equations with the finite difference method. The effect of wavelength, as well as the intensities of pump light and Stokes light, on SBS process are investigated, the results shows the Stokes light takes effect in initial stage mainly, while the pump light works in steady stage; And the stress induced by SBS process varies largely with different wavelength. In addition, the shorter wavelength is, the faster stress develops, which results in damage to materials easier; The induced stress by 3 laser is 100 times as large as the lasers. The moment that SBS occurs for 3 laser is 15ns earlier than that for 2 laser.