# Coherent coupling of single molecules to on-chip ring resonators

## TL;DR

This paper demonstrates cryogenic coupling of single organic molecules to on-chip ring resonators, achieving significant extinction dips and Purcell enhancements, paving the way for quantum optical cooperative effects.

## Contribution

It introduces a novel chip-based nanophotonic platform for coupling single molecules to ring resonators with high finesse and measurable Purcell enhancement.

## Key findings

- Extinction dips of 22% from single molecules.
- Purcell enhancements up to 11-fold.
- Resonator finesse around 20.

## Abstract

We report on cryogenic coupling of organic molecules to ring microresonators obtained by looping sub-wavelength waveguides (nanoguides). We discuss fabrication and characterization of the chip-based nanophotonic elements which yield resonator finesse in the order of 20 when covered by molecular crystals. Our observed extinction dips from single molecules reach 22%, consistent with the expected Purcell enhancements up to 11 folds. Future efforts will aim at efficient coupling of a handful of molecules via their interaction with a ring microresonator mode, setting the ground for the realization of quantum optical cooperative effects.