Calculating and optimizing the coupling efficiency of a sinusoidal grating output coupler on an asymmetric waveguide.

摘要

In integrated optics circuits, grating couplers are used to insert or extract the optical energy. In this thesis, the grating coupler is treated as a perturbed waveguide interface. Because of the imperfect interface, one guided mode is converted to a radiation mode. The coupling efficiency is calculated for the conversion of the guided mode to a substrate radiation mode and computer programs are developed to optimize the coupling efficiency. Computer languages FORTRAN and MATHEMATICA are used to calculate the coupling efficiency.