Optical phase shifter design for single and multi-mode waveguide configurations

Abstract

In this paper, we introduce simple design equations for optical phase shifter configurations on both single mode and multimode platforms. The design equations are based on approximate analytical expressions describing the phase shift (difference) between two waveguides, one is considered as the reference guide and the second is considered as the phase shifter. Different layout geometrical configurations have been studied: the step width and the linear tapering waveguide. The validity of the design formula is tested using standard Beam Propagation Method BPM. The obtained results are in good agreement with numerical calculations and allow using these closed form expressions in the optical design of such phase shifters.