Rigorous analysis of the sensitivity of a three layer planar optical waveguides having an adlayer

The sensitivity of a three layer planar waveguide sensor having an adlayer is studied and compared. Using the transfer matrix method the sensitivities of this waveguide are obtained in the presence of adlayer, and without taking any mathematical approximation. It is observed that the obtained sensitivities of this waveguide sensor are the function of adlayer parameters and one can never overlook the adlayer thickness. Also, the obtained sensitivities are compared with the existing results of this waveguide. It is found that these results are different from the reported sensitivities even if the adlayer thickness is much smaller than applied wavelength.