THEORETICAL ANALYSIS OF NONLINEAR OPTICAL WAVEGUIDESENSORS: TE CASE

In the present paper, an analytical theory will be investigated for studying three-layer slab waveguide for sensor applications. The sensor is a proposed nonlinear optical waveguide including a linear thin film with thickness h and dielectric constant ε_f that is surrounded by a substrate with nonlinear permittivity ε_1and a cover with nonlinear permittivity ε_2. Nonlinear environments are of Kerr type. One of the best quantities studied in the research is sensor sensitivity, that is determined with change in effective refractive index N for changing in refractive index of cover medium n_c. Status of obtaining max sensitivity for nonlinear waveguide sensors TE has been investigated and compared with linear sensors. Guide layer has been chosen as ?Si?_3 N_4and GaN and we have applied silica as cover and substrate environment with some percent impurity. Our proposed sensor with sensitivity of S_h= 0. 2798 increases up to 105.433% and thickness of sensor has decrease of h=105 nm up to 41.666% compared to previous proposed sensors of researchers.