Cavity-enhanced continuous-wave microscopy using unstabilized cavities

TL;DR

This paper introduces a cavity-enhanced continuous-wave microscopy method that improves signal-to-noise ratios at fixed damage levels, using a self-imaging cavity to achieve contrast enhancement and a new dark-field imaging technique, even without cavity stabilization.

Contribution

The work demonstrates a novel cavity-enhanced microscopy approach with unstabilized cavities, enabling improved imaging performance and new dark-field imaging for thick samples.

Findings

Enhanced contrast in biological and test samples

Effective imaging with unstabilized cavities

Potential application to ultracold atom imaging

Abstract

Microscopy gives access to spatially resolved dynamics in different systems, from biological cells to cold atoms. A big challenge is maximizing the information per used probe particle to limit the damage to the probed system. We present a cavity-enhanced continuous-wave microscopy approach that provides enhanced signal-to-noise ratios at fixed damage. Employing a self-imaging 4f cavity, we show contrast enhancement for controlled test samples as well as biological samples. For thick samples, the imaging cavity leads to a new form of dark-field microscopy, where the separation of scattered and unscattered light is based on optical path length. We theoretically show that enhanced signal, signal-to-noise, and signal-to-noise per damage are also retrieved when the cavity cannot be stabilized. Our results provide an approach to cavity-enhanced microscopy with unstabilized cavities and might be used to enhance the performance of dispersive imaging of ultracold atoms.