Laser beams with axially symmetric polarization

An analysis of the vector wave equation was conducted. A class of self-simi lar solutions with inhomogeneous polarization corresponding to the resonato r modes is deduced. The modes with inhomogeneous polarization can be select ed by a diffraction element with polarization selectivity used as one of th e resonator mirrors. Diffraction elements with high polarization selectivit y of about 100% are necessary for generating 'pure' radially polarized mode s. The radially polarized beam provides a higher energy efficiency (the pro duct of the depth of the cut by the cutting velocity) for laser cutting met als than the circularly polarized main mode does under the same conditions. The two limiting cases of resonance absorption on the spherical plasma tar get could be realized using axially polarized beams: the resonance absorpti on is maximum in the case of radial polarization and does not occur in the case of azimuthal polarization.