Strong Coupling in a Self-Coupled Terahertz Photonic Crystal

Maria Kaeek,Tal Schwartz,Sharly Fleischer,Michal Roth,Ran Damari

doi:10.1021/acsphotonics.1c00309

Maria Kaeek, Tal Schwartz + Show 3 more

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https://doi.org/10.1021/acsphotonics.1c00309

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Journal: ACS photonics	Publication Date: Jun 17, 2021
Citations: 14	License type: CC BY 4.0

Affiliation: Tel Aviv University

Abstract

Vibrational strong coupling is a phenomenon in which a vibrational transition in a material placed inside a photonic structure is hybridized with its optical modes to form composite light–matter excitations known as vibro-polaritons. Here we demonstrate a new concept of vibrational strong coupling: we show that a monolithic photonic crystal, made of a resonant material, can exhibit strong coupling between the optical modes confined in the structure and the terahertz vibrational excitations of the same material. We study this system both experimentally and numerically to characterize the dispersion of the photonic modes for various sample thicknesses and reveal their coupling with the vibrational resonances. Finally, our time-domain THz measurements allow us to isolate the free induction decay signal from the grating modes as well as from the vibro-polaritons.

Highlights

Vibrational strong coupling is a phenomenon in which a vibrational transition in a material placed inside a photonic structure is hybridized with its optical modes to form composite light−matter excitations known as vibro-polaritons
Strong coupling is a phenomenon that appears when the resonant energy exchange between a confined optical mode and a material transition is faster than any decay process, forming hybrid light−matter states known as polaritons.[1]
Through a combination of experimental measurements and numerical modeling, we demonstrate vibrational strong coupling (VSC) in a monolithic self-coupled photonic crystal operating in the terahertz (THz) regime

Summary

Introduction

Vibrational strong coupling is a phenomenon in which a vibrational transition in a material placed inside a photonic structure is hybridized with its optical modes to form composite light−matter excitations known as vibro-polaritons. The photonic crystal is made of α-lactose (see further details in Supporting Information S1), which has a resonance frequency of 0.53 THz, corresponding to a collective vibrational mode of the molecular lattice.

Results

Conclusion