$\Lambda$-Enhanced Imaging of Molecules in an Optical Trap

TL;DR

This paper demonstrates a non-destructive imaging technique for calcium monofluoride molecules in an optical trap using $ ext{Lambda}$-enhanced gray molasses cooling, significantly improving fluorescence signal while maintaining low temperature.

Contribution

It introduces a $ ext{Lambda}$-enhanced gray molasses cooling method enabling high-fidelity, non-destructive imaging of molecules in optical traps, surpassing previous destructive methods.

Findings

200 times more fluorescence than destructive imaging

Molecules remain at 20 μK temperature

High-fidelity single-molecule detection possible

Abstract

We report non-destructive imaging of optically trapped calcium monofluoride (CaF) molecules using in-situ $\Lambda$-enhanced gray molasses cooling. $200$ times more fluorescence is obtained compared to destructive on-resonance imaging, and the trapped molecules remain at a temperature of $20\,\mu\text{K}$. The achieved number of scattered photons makes possible non-destructive single-shot detection of single molecules with high fidelity.