Reflections from an inhomogeneous slab

The reflection and transmission functions of an inhomogeneous slab are calculated by labeling the wave by the number of reflections it has undergone in the medium. The Riccati equation, satisfied by the reflected amplitude, is decomposed into an infinite set of linear equations by taking into account the number of scatterings taking place inside the medium and is solved by a novel iterative approach. The order-of-scattering reflection functions method presented here and the coupled integral equation approach of the Bremmer solutions for the internal fluxes are set in a unified frame. The solutions of the Riccati equation are computed numerically for the reflection function using the order-of-scattering technique, and it is demonstrated that the method leads to better convergence and stability as compared to usual linearization methods.