Resolution of a Prism Waveguide Spectrum Analyzer

We have studied the resolution of a waveguide spectrum analyzer, based on a prism coupler for mode excitation, as a function of the structural parameters of the waveguide. We show that the limiting resolution of the waveguide spectrum analyzer is determined by the ratio of the chromatic dispersion of the waveguide to the imaginary part of the propagation constant for the leaky mode of the waveguide/coupling prism structure.