Strong light‐matter coupling between a molecular vibrational mode in a PMMA film and a low‐loss mid‐IR microcavity. Issue 3 (17th November 2015)

• Record Type: Journal Article
• Authors: Muallem, Merav; Palatnik, Alex; Nessim, Gilbert D.; Tischler, Yaakov R.
• Is Part Of: Annalen der Physik. Volume 528:Issue 3/4(2016)
• Page Start: 313
• Page End: 320
• Publication Date: 2015-11-17
• Subjects: Dielectric microcavity -- Mid‐IR -- Organic material -- Strong coupling -- Vibrational transitions; Physics -- Periodicals; Chemistry -- Periodicals; 530.05
• DOI: 10.1002/andp.201500282
• Languages: English
• ISSNs: 0003-3804

Abstract

Abstract : We present a microcavity phonon‐polariton system that is derived from coupling cavity‐confined mid‐IR photons to the vibronic transition of an organic material. In particular, to achieve strong phonon‐photon coupling, we coupled the carbonyl stretch vibrational transition of a polymethyl methacrylate film to the photonic resonance of a low optical‐loss microcavity, which consisted of two Ge/ZnS dielectric Bragg reflectors. Transmission measurements show two distinct transmission peaks that are energetically shifted from the bare phonon and cavity resonances, indicating Rabi‐splitting and the realization of polaritonic states. Abstract : Microcavity devices exhibiting strong light‐matter coupling in the mid‐infrared spectral range offer the potential to explore exciting open physical questions pertaining to energy transfer between heat and light and can lead to a new generation of efficient wavelength tunable mid‐infrared sources of coherent light based on polariton Bose‐Einstein Condensation. Vibrational transitions of organic molecules, which often have strong absorption peaks in the infrared and considerably narrower linewidths than organic excitonic resonances, can generate polaritonic states in the mid‐infrared spectral range using microcavity devices. Here, narrow linewidth polaritonic resonances are exhibited in the mid‐infrared by coupling the carbonyl stretch vibrational transition of a polymethyl methacrylate film to the photonic resonance of a low optical‐loss mid‐infrared microcavity, which consisted of two Ge/ZnS dielectric Bragg reflectors. Rabi‐splitting of 14.3 meV is observed, with a 4.4 meV polariton linewidth at anti‐crossing. The large Rabi‐splitting relative to linewidth indicates efficient impedance‐matching between the bare vibrational and photonic states, and suggests molecular‐vibration polaritons incorporated in dielectric microcavities can be an enabling step towards realizing polariton optical switching and polariton condensation in the mid‐infrared spectral range.