Detection of radiatively open systems using an optical cavity

TL;DR

This paper presents a cavity-based detection method for cold atomic ensembles with radiatively open transitions, enabling minimally destructive, rapid, and prolonged measurements of atomic and molecular systems.

Contribution

The paper introduces a novel cavity-based detection scheme exploiting collective strong coupling for open transitions, improving detection efficiency and reducing losses compared to fluorescence methods.

Findings

Effective detection of small atom and molecule numbers.

Reduced losses and minimal destruction during measurement.

Feasibility demonstrated through experimental and theoretical analysis.

Abstract

We experimentally demonstrate a cavity-based detection scheme for a cold atomic ensemble with a radiatively open transition. Our method exploits the collective strong coupling of atoms to the cavity mode, which results in off-resonant probing of the atomic ensemble, leading to a dramatic reduction in losses from the detection cycle. We then show the viability of this frequency measurement for detecting a small number of atoms and molecules by theoretical modelling. Compared with the most commonly used fluorescence method, we show that the cavity-based scheme allows rapid and prolonged detection of the system's evolution with minimal destruction.