Spontaneous Generation of Vortex Array Beams from a Thin-Slice Solid-State Laser with Wide-Aperture Laser-Diode Pumping

TL;DR

This paper demonstrates the spontaneous formation of vortex array beams in a thin-slice solid-state laser using wide-aperture diode pumping, revealing controlled vortex patterns and mode locking phenomena.

Contribution

It introduces a novel method for generating and controlling vortex array beams in solid-state lasers with wide-aperture diode pumping, highlighting spontaneous mode locking and pattern formation.

Findings

Radial and rectangular vortex arrays can be formed with symmetric and asymmetric pump profiles.

Single-frequency rectangular array beams with many vortices are generated.

Vortex formation is linked to transverse mode locking and laser nonlinearity.

Abstract

We studied complex lasing pattern formations in a thin-slice solid-state laser with wide-aperture laser-diode end-pumping. Radial and rectangular vortex arrays were found to be formed in a controlled fashion with symmetric and asymmetric pump beam profiles, respectively. Most of these vortices exhibited single-frequency oscillations arising from a spontaneous process of transverse mode locking of nearly degenerate modes assisted by the laser nonlinearity. Single-frequency rectangular array beams consisting of a large number of vortices, e.g., closely packed 36 or 46 vortex pixels, were generated, originating from Ince-Gaussian modes excited by the asymmetric pumping.