Resonant mode coupling approximation for calculation of optical spectra of photonic crystal slabs

TL;DR

This paper introduces a resonant mode coupling approximation method to efficiently compute optical spectra of stacked photonic crystal slabs, significantly reducing computation time while maintaining accuracy.

Contribution

The paper presents a novel resonant mode coupling approximation technique for calculating optical spectra of photonic crystal slabs, enabling faster computations.

Findings

Reduces computation time significantly

Maintains high accuracy in spectral calculations

Facilitates inverse scattering problem solving

Abstract

We develop the resonant mode coupling approximation to calculate the optical spectra of a stack of two photonic crystal slabs. The method is based on a derivation of the input and output resonant vectors in each slab in terms of the Fourier modal method in the scattering matrix form. We show that using the resonant mode coupling approximation of the scattering matrices of the upper and lower slabs, one can construct the total scattering matrix of the stack. The formation of the resonant output and input vectors of the stacked system is rigorously derived by means of an effective Hamiltonian. We demonstrate that the proposed procedure dramatically decreases the computation time without sufficient loss of accuracy. We believe that the proposed technique can be a powerful tool for fast solving inverse scattering problems using stochastic optimization methods such as genetic algorithms or machine learning.