Abstract

Semiconductor waveguides are widely used in the field of integrated optics as the basis of active and passive devices. Since no analytical solution to the wave equation is available for rib, ridge or strip loaded structures many modelling techniques have been developed to analyze the guiding properties of these structures. These methods vary considerably in accuracy and ease of application. This paper considers two of these analysis methods, the Finite Difference (FD) Method and the Spectral Index (SI) Method, and notes that both approaches can be extended for use in the complex case ie when the local refractive index of the waveguide cross-section may become complex due to the presence of loss or gain. This gives rise to a complex propagation constant. Complex propagation constants obtained from the FD and SI methods are compared for the first time.

© 1993 Optical Society of America