Forward wide-angle light propagation in semiconductor rib waveguides

Area of Science:

• Optics and Photonics
• Computational Electromagnetics
• Semiconductor Device Physics

Background:

• Accurate modeling of light propagation in optical waveguides is crucial for device design.
• Existing methods may have limitations in handling wide-angle propagation or computational efficiency.
• Nonparaxial effects become significant in strongly guiding structures.

Purpose of the Study:

• To derive and validate a novel nonparaxial wide-angle equation for unidirectional light propagation.
• To develop an efficient and accurate numerical solution technique for the derived equation.
• To assess the performance of the new method using a realistic semiconductor rib-waveguide Y junction test case.

Main Methods:

• Derivation of a new nonparaxial wide-angle equation.
• Development of a unitary solution procedure combining split-step fast-Fourier-transform and finite-difference methods.
• Numerical simulation of light propagation in a semiconductor rib-waveguide Y junction.

Main Results:

• Successful derivation of the nonparaxial wide-angle equation.
• Implementation of a rapid unitary solution algorithm.
• Calculated optical losses show good agreement with established Fresnel equation methods for the test case.

Conclusions:

• The new nonparaxial wide-angle equation provides an accurate description of light propagation.
• The developed solution procedure is efficient and suitable for practical applications.
• The method shows promise for analyzing complex waveguide structures like Y junctions.