Double-end polarized pumping scheme combined with off-axis pumping technique has been first introduced to generate vortex beams in a z-type cavity. By employing double-end pumping, two different transverse modes can be excited simultaneously. The phase delay between these two modes can be finely tuned by manipulating the cavity structure. Direct emission of a chirality controllable Laguerre Gaussian LG(01) vortex beam with slope efficiency of more than 40% has been realized by a double-end polarized pumped Yb:KYW laser. Other modes, such as dual-LG(01) mode, cross-shaped mode, and LG(10) mode, have also been demonstrated from our laser setup. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

This work was published on OPTICS EXPRESS,26(21),26925-26932.titled Direct generation of vortex beams from a double-end polarized pumped Yb:KYW laser.