# Full-field cavity enhanced microscopy techniques

## TL;DR

This paper compares three cavity-based microscopy techniques that leverage quantum effects to achieve sensitivities surpassing the standard quantum limit, advancing high-sensitivity, low-damage imaging methods.

## Contribution

It provides a theoretical and numerical comparison of CW cavity enhanced, cavity ring-down, and multi-pass microscopy techniques based on self-imaging cavities, highlighting their potential for quantum-enhanced sensitivity.

## Key findings

- All three methods can surpass the standard quantum limit in sensitivity.
- Theoretical and numerical analysis demonstrates the advantages of cavity-based quantum microscopy.
- Multi-pass microscopy exploits multiple photon-sample interactions for enhanced sensitivity.

## Abstract

Quantum enhanced microscopy allows for measurements at high sensitivities and low damage. Recently, multi-pass microscopy was introduced as such a scheme, exploiting the sensitivity enhancement offered by multiple photon-sample interactions. Here we theoretically and numerically compare three different contrast enhancing techniques that are all based on self-imaging cavities: CW cavity enhanced microscopy, cavity ring-down microscopy and multi-pass microscopy. We show that all three schemes can lead to sensitivities beyond the standard quantum limit.