A general method for analyzing distributed feedback waveguides

In this paper, we report a novel method for analyzing one-dimensional distributed feedback waveguides. In this new method, a waveguide is divided into a number of segments following the weak feedback division principle which assumes that, the reflection in each segment is weak enough so that relevant transmission loss of the segment and the second and higher order reflections in the segment can be neglected. Reflection and transmission coefficients of individual segments can be easily derived, and then the global reflection and transmission characteristics of the whole waveguide can be obtained with the use of the transfer matrix method. We use the method to analyze the reflection and transmission characteristics of uniform Bragg grating with arbitrary, and compare its results with those from the coupled mode method and the effective index method. The proposed method has a wider application range than the coupled mode method and much less calculation amount than the effective index method