Strong Optomechanical Coupling in Nanobeam Cavities based on Hetero Optomechanical Crystals.

Zhilei Huang,Wei Zhang,Fang Liu,Kaiyu Cui,Xue Feng,Yidong Huang,Yongzhuo Li

doi:10.1038/srep15964

Abstract

Nanobeam cavities based on hetero optomechanical crystals are proposed. With optical and mechanical modes separately confined by two types of periodic structures, the mechanical frequency is designed as high as 5.88 GHz. Due to the optical field and the strain field concentrated in the optomechanical cavity and resembling each other with an enhanced overlap, a high optomechanical coupling rate of 1.31 MHz is predicted.

Highlights

IntroductionWith optical and mechanical modes separately confined by two types of periodic structures, the mechanical frequency is designed as high as 5.88 GHz. Due to the optical field and the strain field concentrated in the optomechanical cavity and resembling each other with an enhanced overlap, a high optomechanical coupling rate of 1.31 MHz is predicted
Nanobeam cavities based on hetero optomechanical crystals are proposed
Further increment of the mechanical frequency and optomechanical coupling rate is hindered by the conventional optomechanical-crystal designs, in which the confinement of both mechanical and optical modes is achieved by the same periodical structure[9], and the localized optical and mechanical modes are within the photonic and phononic bandgaps simultaneously formed by one periodic structure

Summary

Introduction

With optical and mechanical modes separately confined by two types of periodic structures, the mechanical frequency is designed as high as 5.88 GHz. Due to the optical field and the strain field concentrated in the optomechanical cavity and resembling each other with an enhanced overlap, a high optomechanical coupling rate of 1.31 MHz is predicted. Thanks to the rapid development of nanofabrication technology, cavity optomechanical systems have been realized in several types of systems, including vibrating microtoroids[3], stacked microdisks[8], and optomechanical crystals[9] or, referred to as phoxonic crystals[4,10,11,12,13], which acts as both photonic crystals and phononic crystals Among these systems, optomechanical crystals have attracted great interest because their relatively high mechanical frequency[2] makes the mechanical vibration resistant to the thermal fluctuation[14] and high optomechanical coupling rate[15,16] results in strong interaction strength between photons and phonons in the cavities. A record high optomechanical coupling rate of 1.31 MHz is predicted

Methods

Results

Conclusion