Generation of a radially polarized laser beam in a single microchip Nd:YVO_4 laser

Abstract

A radially polarized beam was generated in a microchip Nd:YVO4 laser by shaping the pump profile to be a group of focused plane waves, the directions of which are located on a conical surface. The oblique incident pump beam induces thermal lensing combined with birefringence to distinguish the radial ray from the azimuthal ray to achieve radial polarization. The average contrast ratio was 23.6 when the pump power was between 3.06 and 4.27 W.