Vacuum-enhanced optical nonlinearities with organic molecular photoswitches

TL;DR

This paper introduces a cavity QED scheme utilizing organic molecular photoswitches to achieve vacuum-induced transparency and enhanced cross-phase modulation, enabling low-light all-optical switching despite disorder.

Contribution

It demonstrates a novel approach to induce vacuum transparency and significant nonlinearities using disordered organic molecules in microcavities.

Findings

Vacuum-induced transparency achieved with organic photoswitches.

Cross-phase modulation surpasses absorption loss limits.

Potential for low-photon-number all-optical switching.

Abstract

We propose a cavity QED scheme to enable cross-phase modulation between two arbitrarily weak classical fields in the optical domain, using organic molecular photoswitches as a disordered intracavity nonlinear medium. We show that a long-lived vibrational Raman coherence between the $cis$ and $trans$ isomer states of the photoswitch can be exploited to establish the phenomenon of vacuum-induced transparency (VIT) in high-quality microcavities. We exploit this result to derive an expression for the cross-phase modulation signal and demonstrate that it is possible to surpass the detection limit imposed by absorption losses, even in the presence of strong natural energetic and orientational disorder in the medium. Possible applications of the scheme include the development of organic nanophotonic devices for all-optical switching with low photon numbers.