Propagation characteristics of some intricate planar waveguides of practical interest by finite difference method

Using the finite difference method (FDM), we analyse some practically interesting planar waveguide structures and develop the proper FDM algorithm to predict the relevant transverse electric and transverse magnetic modes with their propagation constants (b) over a long range of normalised frequency (V). In order to crosscheck our results from FDM, we use the step index profile, parabolic index profile and complementary error index profile as a test case to standardise our program. Then, with our program, we consider two more structures such as, diffused planar waveguide and planar directional coupler, to predict the corresponding b−V curves which are yet to be, completely, analysed by FDM.