Stability Formulation for Integrated Opto-mechanic Phase Shifters

Yigit Ozer,Serdar Kocaman

doi:10.1038/s41598-018-20405-1

Abstract

Stability of opto-mechanical phase shifters consisting of waveguides and non-signal carrying control beams is investigated thoroughly and a formula determining the physical limitations has been proposed. Suggested formulation is not only beneficial to determine physical strength of the system but also advantageous to guess the response of the output to the fabrication errors. In the iterative analysis of cantilever and double-clamped beam geometrical configurations, the stability condition is revealed under the strong inter-dependence of the system parameters such as input power, device length and waveguide separation. Numerical calculations involving effective index modifications and opto-mechanic movements show that well-known cantilever beams are unstable and inadequate to generate φ = 180° phase difference, while double-clamped beam structures can be utilized to build functional devices. Ideal operation conditions are also presented in terms of both the device durability and the controllability of phase evolution.

Highlights

Integration of many photonic devices such as modulators, phase shifters and interferometers on the same chip[1,2] is a prominent way to enhance performance of new generation communication[3] and quantum information processing[4,5] technologies as well as quantum data storage[6] techniques
The usual opto-mechanic phase shifter structure consists of one waveguide and one non-signal carrying control beam, which is either a cantilever or a double-clamped beam and placed parallel to the signal carrying waveguide[9,10,40,41]
While effective index values of this system are calculated by using Finite Element Method (FEM), Euler-Bernoulli beam theory[42] is utilized for the precise calculation of deflection as a result of optical gradient force

Summary

Introduction

Integration of many photonic devices such as modulators, phase shifters and interferometers on the same chip[1,2] is a prominent way to enhance performance of new generation communication[3] and quantum information processing[4,5] technologies as well as quantum data storage[6] techniques Main motivation of these systems comes from the minimization of power consumption and coupling losses for faster, accurate and compact implementations[7,8]. The capacitive actuator is the conventional micro electro-mechanical system (MEMS) based device and the effective index change is provided from the conversion of the electrical signal into a mechanical movement[32,35] These structures require two metalized contact layers, which are desired to be placed far away from waveguides in order to limit the absorption of the light in the metal. In comparison, ~8–17 mW laser power may provide similar performance in the opto-mechanical (all-optical) components as thoroughly explained

Methods

Results

Conclusion