Validation of ray optics capability to analyze the transfer behavior of bent optical slab waveguides

Integrated optical waveguides on PCB level are a promising technology to enhance data transfer rates. For minimal tolerance requirements these waveguides are multimodal, accordingly ray optical methods are used to analyze the transfer behavior. In this context the limits of ray optical methods are not well-known. It is the aim of this work to validate these methods by comparison with a wave analysis of bent dielectric slab waveguides. This analysis uses quasi-guided modes that are appropriate to simulate the optical power flow after passing a 90° bend. The fields of a Gaussian beam serve as reference source.