# On the dragging of light by a rotating medium

## TL;DR

This paper investigates how light's polarization and transmitted image are affected by passing through a rotating medium, revealing that orbital angular momentum influences image rotation while spin angular momentum affects polarization.

## Contribution

It extends previous analyses by incorporating orbital angular momentum into the wave equation, explaining the distinct effects on polarization and image rotation.

## Key findings

- Optical polarization rotation is linked to spin angular momentum.
- Image rotation is connected to orbital angular momentum.
- Wave equation inside rotating media requires an additional term for angular momentum.

## Abstract

When light is passing through a rotating medium the optical polarisation is rotated. Recently it has been reasoned that this rotation applies also to the transmitted image (Padgett et al. 2006). We examine these two phenomena by extending an analysis of Player (1976) to general electromagnetic fields. We find that in this more general case the wave equation inside the rotating medium has to be amended by a term which is connected to the orbital angular momentum of the light. We show that optical spin and orbital angular momentum account respectively for the rotation of the polarisation and the rotation of the transmitted image.