Spectral response of vibrational polaritons in an optomechanical cavity

Abstract

Vibrational strong coupling provides a convenient way to modify the energy of molecular vibrations and to explore controlling chemical reactivity. In this work, we theoretically report the various vibrational anharmonicities that modulate the dynamics of optomechanically coupled W(CO)6-cavity. The optomechanical free-space cavity consists of movable photonic crystal (PhC) membrane, which creates the photonic bound states to interact with the molecular vibration. This coupled system is used for realizing strong optomechanical dispersive or dissipative type coupling, which provides a platform to explore the new regimes of the optomechanical interaction. The addition of different strong coupling and mechanical (nuclear) anharmonicities to the optical cavity establishes the modified splitting dynamics in the absorption spectrum and shows that the ground-state bleach of coupled W(CO)6- cavity has a broad, multisigned spectral response. This work points out the possibility of systematic and predictive modification of the multimode spectroscopy of optomechanical W(CO)6-cavity polariton system.

Molecular Polaritons for Chemistry, Photonics and Quantum Technologies

“…Equally pivotal, theoretical inquiries have proposed the incorporation of mechanical modes alongside molecular light− matter strong coupling. Barbhuiya et al 156 proposed a model system featuring W(CO) 6 within a photonic crystal (PhC) optomechanical cavity (Figure 8c), where the engaged molecular vibrational mode is strongly coupled with the photonic cavity mode, forming polaritons. Meanwhile, mechanical−photonic coupling results in optomechanical induced transparency (OMIT), leading to a narrow frequency window with high transmission, and greatly alters the line shape of the cavity photonic mode.…”

“…A promising hybrid cavity in light–matter strong coupling is the optomechanical cavity, − which involves the interaction between the optical cavity mode and the mechanical mode. The mechanical mode often pertains to the vibrational motion of a membrane within the optical cavity or the mechanical oscillation of a spring mounted on one of the photonic cavity mirrors ,, (Figure a, left panel).…”

“…(c) Illustration of a double-photonic crystal slab cavity (DPhC) with a mode of frequency ω a and molecular [W­(CO) 6 ] transition frequency ω c , coupled to the PhC slab vibrational mode of frequency, ω m , and the W­(CO) 6 -cavity coupling strength Ω R . Reproduced with permission from ref . Copyright 2022 American Institute of Physics.…”