Design of low-loss and low crosstalk AWG through Fraunhofer diffraction analysis and beam propagation method

This paper presents an optimal design of the waveguide separation and the orientation angle of the slabs for the arrayed waveguide gratings (AWGs) with low crosstalk and low loss. To demonstrate the effectiveness of the proposed method, a 16 × 16 AWG using silica-based sol-gel material is designed as an example to match our prescribed specifications. The performance of the designed AWG is perfectly verified by a numerical simulation using the beam propagation method (BPM). The results indicate that the proposed methodology for determining the optimal waveguide separation and the orientation angle of the slabs is very simple and useful to obtain a low-crosstalk and low-loss AWG.