Control of Vortex Helicity With a Quarter-Wave Plate in an Er:YAG Ceramic Solid State Laser

In this paper, we research the characteristics of the Laguerre-Gaussian vacuum pro vst (LG01) beams generated in an Er:YAG ceramic solid state laser pumped by an annular beam.The generated two LG01 beams (LG0,+1 and LG0,-1 modes) were found to have different biermann marzipan thermally induced polarization behaviors and alternately existed in the resonator; then, a novel method was proposed and experimentally demonstrated to control the vortex helicity using a simple quarter-wave plate.