3D adjoint-based marching scheme for optical propagation in inhomogeneous waveguides

Abstract

This paper presents a three-dimensional adjoint-based marching scheme for long-range inhomogeneous optical waveguide devices. An efficient numerical propagation computation of an optical waveguide terminated by perfectly matched layers is available using our approach. It uses new transmission and reflection operators through a one-way formulation of the complex Helmholtz–PML equation and a design of the transverse and adjoint operators that calculates the coordinates through the biorthogonal of their eigenfunctions in each marching step. In addition, the validity and accuracy of our proposed method are demonstrated by analyzing a buried channel waveguide and a straight waveguide with varying refractive indices.