Observation of triangular-lattice pattern in nonlinear wave mixing with optical vortices

TL;DR

This paper reports the observation of a triangular-lattice pattern in nonlinear optical wave mixing involving vortices, revealing how vortex charge influences lattice structure and orientation, with potential applications in wavelength conversion.

Contribution

It demonstrates the formation of triangular-lattice patterns in nonlinear wave mixing with optical vortices and explores how vortex charge and phase conjugation affect the pattern.

Findings

Triangular-lattice patterns are observed in nonlinear wave mixing with optical vortices.

Lattice orientation depends on the vortex topological charge.

The pattern works across various spatial field structures.

Abstract

A triangular-lattice pattern is observed in light beams resulting from the spatial cross modulation between an optical vortex and a triangular shaped beam undergoing parametric interaction. Both up- and down-conversion processes are investigated, and the far-field image of the converted beam exhibits a triangular lattice. The number of sites and the lattice orientation are determined by the topological charge of the vortex beam. In the down-conversion process, the lattice orientation can also be affected by phase conjugation. The observed cross modulation works for a large variety of spatial field structures, and could replace solid-state devices at wavelengths where they are not yet available.