Broadband opto-mechanical phase shifter for photonic integrated circuits

TL;DR

This paper proposes a broadband opto-mechanical phase shifter for photonic integrated circuits that uses optical gradient forces to achieve phase shifts with low power and discusses its design, performance, and noise effects.

Contribution

It introduces a novel opto-mechanical phase shifter design that achieves efficient phase shifting with low power using a deformable nanostring structure.

Findings

A π phase shift can be achieved with 0.64 mW power.

The device length is about 50 μm.

The phase shifter's performance is influenced by geometry, power, and boundary conditions.

Abstract

A broadband opto-mechanical phase shifter for photonic integrated circuits is proposed and numerically investigated. The structure consists of a mode-carrying waveguide and a deformable non-mode-carrying nanostring, which are parallel with each other. Utilizing the optical gradient force between them, the nanostring can be deflected. Thus the effective refractive indices of the waveguide is changed with the deformation, and further causes a phase shift. The phase shift under different geometry sizes, launched powers and boundary conditions are calculated and the dynamical properties as well as the thermal noise's effect are also discussed. It is demonstrated that a $\pi$ phase shift can be realized with only about 0.64 mW launched power and 50 $\mu m$ long nanostring. The proposed phase shifter may find potential usage in future investigation of photonic integrated circuits.