Directgeneration of eye-safe single-and dual-vortexlasersvia off-axis pumping of the active medium

TL;DR

This paper presents a simple, efficient method for directly generating eye-safe single- and dual-vortex lasers using off-axis pumping of a Nd:YAG laser cavity, enabling new applications in various fields.

Contribution

It introduces a novel off-axis pumping technique to produce vortex laser modes directly in a compact, solid-state laser, and proposes a new method to determine vortex handedness.

Findings

Achieved direct generation of single- and dual-vortex lasers at eye-safe wavelengths.

Demonstrated simultaneous dual-wavelength vortex laser operation.

Developed a method to determine vortex handedness using a coated mirror.

Abstract

A simple and high-efficiency method for direct generation of all-solid-state single- and dual-vortex lasers operating at eye-safe wavelengths is reported in a compact diode-end-pumped Nd:YAG laser cavity. By off-axis pumping of the Nd:YAG in two orthogonal directions, the original cavity mode, fundamental Gaussian mode (TEM00), is directly transformed into first-order Laguerre-Gaussian (LG01) mode with single- or dual-vortex structures depending on the degree of the off-axis pumping. Moreover, the single- and dual-vortex lasers can be produced in simultaneous eye-safe dual-wavelength operation with the aid of an intracavity etalon. At the same time, a novel method to determine the handedness of achieved vortex lasers by using a plane-concave mirror with suitable coating is also proposed. This method can be perfectly applied to generate vortex lasers at other emissions bands for various applications by using different laser gain mediums. This work paves a general way to simple and efficient realization and determination of vortex lasers.