Transformation of high-power laser beam polarization by resonant excitation of surface electromagnetic waves on metallic diffraction gratings

We report the new method of highly efficient transformation of linear polarized laser beam into another beam, with any required polarization performed by reflection grating. The parameters of this grating were calculated theoretically. The grating converters with a reflectivity of R >= 96% for transformation of linearly polarized CO 2 laser beam into a circular polarized beam have been fabricated. The efficiency of these converters included in a 1.5 kW CO 2 laser technological system for metal cutting is demonstrated.