Ultraviolet waveband vector beams generation assisted by the nonlinear frequency conversion

Abstract

Vector beams with a nonseparable polarization distribution are almost thoroughly studied from their generation to application in infrared and visible regimes. Until now, the nonlinear generation of ultraviolet vector beams is only focused on the nonlinear optical processes of gas molecules, which seriously impacts its further applications due to the unstable property. Here, we present a study on the generation of ultraviolet vector beams assisted by the nonlinear frequency conversion processes in potassium dihydrogen phosphate crystals. The vectorial properties of the generated ultraviolet waveband vector beams are characterized in both theoretical and experimental environments. The proposed method paves the way for the generation of extreme ultraviolet vector beams with solid-state nonlinear crystal, which is a more compact and stable way compared with the gas nonlinear method. This work also opens a route for photolithographic techniques and laser processing based on ultraviolet waveband vector beams.