# Slow and fast light enhanced light drag in a moving microcavity

## TL;DR

This paper demonstrates how slow and fast light effects in a moving microcavity can significantly enhance light drag, enabling compact motion sensing and ultrafast signal processing.

## Contribution

It presents the first experimental demonstration of enhanced light drag using stimulated Brillouin scattering in a moving microcavity, achieving a dispersion enhancement factor of up to 10^4.

## Key findings

- Light drag effect is significantly enhanced by dispersion in a microcavity.
- The system size can be reduced to micrometer scale due to the enhancement.
- Potential applications in motion sensing and ultrafast signal processing.

## Abstract

Fizeau experiment, inspiring Einstein's special theory of relativity, reveals a small dragging effect of light inside a moving medium. Dispersion can enhance such light drag according to Lorentz's predication. Here we experimentally demonstrate slow and fast light enhanced light drag in a moving optical microcavity through stimulated Brillouin scattering induced transparency and absorption. The strong dispersion provides an enhancement factor up to ~10^4, greatly reducing the system size down to the micrometer range. These results may offer a unique platform for a compact, integrated solution to motion sensing and ultrafast signal processing applications.