Inverse problem of bragg's scattering for measuring the spectrum surface roughness in the optical gradient waveguide

A new method for measuring the spectrum of surface roughness based on Bragg scattering, is proposed. This method is characterized by its high precision of measurement of the spatial amplitudes and frequencies. Was determined the rang of spatial frequencies (periods) of harmonics in the roughness spectrum surfaces (0,π) (0; π). When the rotatiońs angle of grating is (0,π/4) will be a forward scattering or Bragǵs deflector. At rotatiońs angle of grating is (π/2,π/4) or (-3π/4,-π/2) will a Bragǵs mirror. The measurements are made in a gradient waveguide, obtained by ion exchange method. © 2017 SPIE.