A Watt-Level, High-Quality LG0,±1 Vortex Beam made from a Nd:YVO4 Laser Pumped by an Annular Beam

Abstract

In this work, we demonstrate a Watt-level, high-quality Laguerre–Gaussian (LG) LG0±1 vortex mode directly output from an end-pumped Nd:YVO4 laser by using an axicon-based annular pump beam. A theoretical model for the annular beam end-pumped solid-state laser with an LG vortex mode output was established. Chirality control of the vortex laser was achieved by carefully tilting the output coupler. Watt-level 1064 nm lasers with pure LG0,1/LG0,−1 vortex mode, and the incoherent superposition mode of LG0,1 odd and even petal modes, were achieved successively in our experiments. The intensity profile of the generated pure LG0,1 vortex laser was measured, and it can be well fitted by using the standard expression of the LG0,1 vortex mode. The beam quality of the pure LG0,1 mode is Mx2 = 2.01 and My2 = 2.00 along the x-axis and y-axis, respectively. Our study demonstrates that that axicon-based annular pumping has great potential in developing high-power vortex solid-state lasers with simple and compact structures.