Transmissive optomechanical platforms with engineered spatial defects

TL;DR

This paper explores how engineered spatial defects in quasi-periodic optomechanical arrays can localize light modes and significantly enhance photon-phonon coupling, expanding on previous work with periodic arrays.

Contribution

It introduces the study of quasi-periodic arrays with defects, demonstrating enhanced optomechanical coupling through light localization and transmissive regime access.

Findings

Defects induce light mode localization in quasi-periodic arrays.

Enhanced linear and quadratic couplings observed due to defect-induced localization.

Transmissive regime window can be exploited for coupling enhancement.

Abstract

We investigate the optomechanical photon-phonon coupling of a single light mode propagating through an array of vibrating mechanical elements. As recently shown for the particular case of a periodic array of membranes embedded in a high-finesse optical cavity [A. Xuereb, C. Genes and A. Dantan, Phys. Rev. Lett., \textbf{109}, 223601, (2012)], the intracavity linear optomechanical coupling can be considerably enhanced over the single element value in the so-called \textit{transmissive regime}, where for motionless membranes the whole system is transparent to light. Here, we extend these investigations to quasi-periodic arrays in the presence of engineered spatial defects in the membrane positions. In particular we show that the localization of light modes induced by the defect combined with the access of the transmissive regime window can lead to additional enhancement of the strength of both linear and quadratic optomechanical couplings.