Passively Q-switching cylindrical vector beam fiber laser operating in high-order mode

TL;DR

This paper demonstrates a high-efficiency, passively Q-switched cylindrical vector beam fiber laser operating directly in high-order modes without mode converters, achieving stable pulses and polarization control.

Contribution

It introduces a novel all-fiber Q-switched CVB laser in high-order mode that simplifies design and improves efficiency by eliminating mode converters.

Findings

Achieved stable Q-switching with 39% slope efficiency.

Generated radially and azimuthally polarized beams.

Proved feasibility of direct high-order mode oscillation.

Abstract

We experimentally demonstrate a linear-cavity all-fiber passively Q-switching cylindrical vector beam (CVB) laser operating in high-order mode. This CVB fiber laser operates without any mode converter which always leads to high insertion loss, and it can realize high efficiency. In this fiber laser, the stable Q-switching pulse is achieved with a slope efficiency of 39%. By properly adjusting the polarization controllers, radially polarized and azimuthally polarized beams can be obtained. Our work proves the feasibility of achieving the stable Q-switching CVB pulse with high-order mode directly oscillating, and it may have an enormous potential for enhancing the efficiency.