Evaluation of propagation loss of lithographically etched optical waveguide based on scalar and vector models

In this paper, the propagation losses of optical waveguides are evaluated via scalar and vector beam propagation method (BPM). Waveguides with different structural parameters are investigated with detailed numerical simulations. It is found that in the weakly guided regime, the scalar model agrees well with the vector model, while in the strongly guided regime, the vector model is required to generate accurate loss predictions.