Generation of high-quality terahertz OAM mode based on soft-aperture difference frequency generation

TL;DR

This paper demonstrates a method to generate high-quality, tunable terahertz vortices with orbital angular momentum using soft-aperture difference frequency generation, achieving specific mode qualities and power levels.

Contribution

It introduces a novel approach for producing high-quality terahertz OAM modes with tunability and specific topological charges using soft-aperture difference frequency generation.

Findings

Achieved terahertz vortex generation with topological charge ±1 in 2-6 THz range.

Maximum power of ~3.3 μW at 4 THz.

Demonstrated high-quality OAM mode in the generated THz vortices.

Abstract

We demonstrate the generation of high-quality tunable terahertz (THz) vortices in an eigenmode by employing soft-aperture difference frequency generation of a vortex output and a Gaussian mode. The generated THz vortex output exhibits a high-quality orbital angular momentum (OAM) mode with a topological charge of $\ell_{THz}=\pm1$ in a frequency range of 2-6 THz. The maximum average power of the THz vortex output obtained was ~3.3 $\mu$W at 4 THz.