Simple Coherent Polarization Manipulation Scheme for Generating High Power Radially Polarized Beam

摘要

We present a simple novel scheme that converts a Gaussian beam into anapproximated radially polarized beam using coherent polarization manipulationtogether with Poynting walk-off in birefringent crystals. Our scheme alleviatesthe interferometric stability required by previous schemes that implementedthis coherent mode summation using Mach-Zehnder-like interferometers. Asymmetrical arrangement of two walk-off crystals with a half-wave plate, allowscoherence control even when the laser has short temporal coherence length. Wegenerated 14 watts of radially polarized beam from an Ytterbium fiber laser,only limited by the available fiber laser power.