Generation of sub-diffraction-limited pure longitudinal magnetization by the inverse Faraday effect by tightly focusing an azimuthally polarized vortex beam

In this Letter we report on the generation of sub-diffraction-limited pure longitudinal magnetization in optomagnetic materials. The interaction between polarization singularities of cylindrically polarized beams and optical vortices in the tight focus of a high numerical-aperture objective as well as the induced magnetic fields through the inverse Faraday effect are investigated. A pure longitudinal magnetization distribution throughout the entire focal plane, which has a 15% reduction in the lateral full width at half-maximum, is achieved by tightly focusing an azimuthally polarized vortex beam.