Optical simulations of GaAs/AlGaAs thin-film waveguides were performed for investigating the dependence of the modal behavior on waveguide geometry and the resulting analytical sensitivity. Simulations were performed for two distinct mid-infrared wavelengths, thereby demonstrating the necessity of individually designed waveguide structures for each spectral regime of interest. Hence, the modal behavior, sensitivity, and intensity of the evanescent field were investigated via modeling studies at
