We develop new generalized four-wave-model-based waveguide mode equations for both isotropic and anisotropic systems by taking into account the influence of the incident light. These new mode equations eliminate the inherent deficiency in the conventional waveguide model, in which the action of incident light was neglected. Further, a peak-value-search (PVS) numerical method is developed to solve the four-wave-model-based mode equations. The PVS method has significant advantages in that accurate refractive index and thickness can be obtained without prior knowledge of the thickness of the air gap.
© 2004 Optical Society of America
Tao Liu and Robert J. Samuels, "Physically correct theoretical prism waveguide coupler model," J. Opt. Soc. Am. A 21, 1322-1333 (2004)