Optics of a Gas of Coherently Spinning Molecules

TL;DR

This paper investigates how a gas of rapidly spinning molecules affects passing light, showing polarization inversion and frequency shifts controllable by molecular rotation, supported by recent experimental results.

Contribution

It introduces a theoretical framework explaining the optical effects of coherently spinning molecules and matches experimental observations of the rotational Doppler effect.

Findings

Circular polarization inversion of probe light

Frequency shift controllable by molecular rotation

Agreement with recent experimental data

Abstract

We consider optical properties of a gas of molecules that are brought to fast unidirectional spinning by a pulsed laser field. It is shown that a circularly polarized probe light passing through the medium inverts its polarization handedness and experiences a frequency shift controllable by the sense and the rate of molecular rotation. Our analysis is supported by two recent experiments on the laser-induced rotational Doppler effect in molecular gases, and provides a good qualitative and quantitative description of the experimental observations.