AN IMPROVED APPROACH FOR THE WAVE-EQUATION SOLUTION OF GRADED-INDEX WAVE-GUIDE

An improved way to solve the wave equation for the graded-index planar waveguide is presented. An analytic solution correct up to the first order of the dielectric function gradient is obtained for a linearly g raded medium and is applied to calculate the optical confinement facto rs in a number of graded-index waveguides of laser diode structure. Fo r a multilayer sectioning method, the number of section layers require d to get a reasonable error is greatly reduced by considering the grad ient in each sectioned layer instead of using the average value, espec ially in the case of linear grading. The advantages and limits of the solution are discussed. (C) 1995 American Institute of Physics.