Nonlinear Zel'dovich effect: Parametric amplification from medium rotation

TL;DR

This paper proposes a nonlinear optics system where rotating media induce parametric amplification of light with orbital angular momentum, revealing a nonlinear Zel'dovich effect linked to symmetry breaking.

Contribution

It introduces a novel nonlinear optics setup demonstrating amplification via medium rotation, connecting to fundamental physics and expanding understanding of Zel'dovich-like effects.

Findings

Amplification occurs at high rotation rates due to phase mismatch.

Rotation breaks anti-PT symmetry, enabling energy transfer.

The system links nonlinear optics with fundamental rotational scattering phenomena.

Abstract

The interaction of light with rotating media has attracted recent interest for both fundamental and applied studies including rotational Doppler shift measurements. It is also possible to obtain amplification through the scattering of light with orbital angular momentum from a rotating and absorbing cylinder, as proposed by Zel'dovich more than 40 years ago. This amplification mechanism has never been observed experimentally yet has connections to other fields such as Penrose superradiance in rotating black holes. Here we propose a nonlinear optics system whereby incident light carrying orbital angular momentum drives parametric interaction in a rotating medium. The crystal rotation is shown to take the phase-mismatched parametric interaction with negligible energy exchange at zero rotation to amplification for sufficiently large rotation rates. The amplification is shown to result from breaking of anti-PT symmetry induced by the medium rotation.