Comparison between the matrix method and the coupled-wave method in the analysis of Bragg reflector structures

We compare the reflectivity spectrum and phase-change spectrum of Bragg reflectors obtained by the matrix method and the coupled-wave method. We show that the results obtained by the two methods agree well generally and the discrepancy between the results obtained by the two methods increases as the fractional refractive-index difference between adjacent layers increases and (or) the average absorption loss increases because of the approximations inherent in the coupled-wave method for the analysis of multiple dielectric layers.