Parametric amplification of orbital angular momentum beams based on light-acoustic interaction

TL;DR

This paper demonstrates efficient stimulated Brillouin amplification of orbital angular momentum beams, preserving their phase structure and enabling potential applications in OAM multiplexing.

Contribution

First study to explore stimulated Brillouin amplification for OAM beams, showing noise-free amplification and mode independence in different geometrical frames.

Findings

OAM signals can be amplified efficiently without noise.

Output modes are independent of pump modes and geometrical frames.

OAM states can be coherently transferred to phonons.

Abstract

A high fidelity amplification of beams carrying orbital angular momentum (OAM) is very crucial for OAM multiplexing and other OAM-based applications. Here, we report the first study of stimulated Brillouin amplification (SBA) for OAM beams, the energy conversion efficiency of photon-phonon coupling and the phase structure of amplified signals are investigated in collinear and noncollinear frame systems, respectively. Our results demonstrate that the OAM signals can be efficiently amplified without obvious noise introduced, and the modes of output signal are independent of the pump modes or the geometrical frames. Meanwhile, an OAM state depending on the optical modes and the geometrical frames is loaded into phonons by coherent light-acoustic interaction, which reveals more fundamental significance and a great application potential in OAM-multiplexing.