Normalized analysis for the sensitivity optimization of integrated optical evanescent-wave sensors

Closed-form analytical expressions and normalized charts provide the conditions for the maximum sensitivity of transverse electric (TE) and transverse magnetic (TM) evanescent-wave step-index waveguide sensors. The analysis covers both cases where the measurand is homogeneously distributed in the semi-infinite waveguide cover, and where it is an ultrathin film at the waveguide-cover interface.