Effect of waveguide optical scattering on the integrated optical spectrum analyzer dynamic range

The dynamic range limited by optical scattering in the integrated optical spectrum analyzer is considered. Calculations of dynamic range as a function of waveguide attenuation and surface roughness characteristics are presented. Dynamic range is found to decrease with increasing attenuation, to be nearly independent of the surface roughness correlation length for a fixed attenuation, and to be independent of the Fourier transform lens focal length. Adjacent channel rejection is found to fall off slowly. The effect of lens scattering is shown only to be important for cases in which waveguide scattering is very small and lens scattering is very high.