Integrated molecular optomechanics with hybrid dielectric-metallic resonators

TL;DR

This paper extends molecular optomechanics to hybrid dielectric-plasmonic resonators, demonstrating enhanced Raman scattering through complex mode interactions, Fano lineshapes, and high-Q resonator integration for improved molecular sensing.

Contribution

It introduces a formalism for hybrid resonators with multiple modes, enabling prediction and optimization of Raman enhancement and integrated device design.

Findings

Raman enhancement depends on pump and LDOS modifications.

Fano lineshapes enable strong Raman enhancement with high-Q modes.

Demonstration of a fully integrated high-Q Raman resonator.

Abstract

Molecular optomechanics stems from the description of Raman scattering in the presence of an optical resonator using a cavity optomechanics formalism. We extend the molecular optomechanics formalism to the case of hybrid dielectric-plasmonic resonators, with multiple optical resonances and with both free-space and waveguide addressing. We demonstrate how the Raman enhancement is the product of a pump enhancement and a modified LDOS, that simply depend on the complex response functions of the hybrid system. The Fano lineshapes that result from hybridization of a broadband and narrowband modes allows reaching strong Raman enhancement with high-Q resonances, paving the way towards sideband resolved molecular optomechanics. The model allows prediction of the Raman emission ratio into different output ports and enables demonstrating a fully integrated high-Q Raman resonator exploiting multiple cavity modes coupled to the same waveguide.