An asymmetric optical vortex generated by a spiral refractive plate

作者：Kotlyar V V^*; Kovalev A A; Stafeev S S; Nalimov A G

来源：Journal of Optics, 2013, 15(2): 025712.

DOI：10.1088/2040-8978/15/2/025712

• refractive spiral phase plate
• optical vortex
• thin element
• transmittance function
• microrelief
• Huygens-Fresnel principle

Using a revised Kirchhoff diffraction integral and the finite-difference time-domain method we show that an optical vortex generated by a refractive spiral plate with a relief step has an asymmetric profile. The annular diffraction pattern in the optical vortex beam cross-section is found to be disturbed not only for near-field diffraction but also for the Fresnel zone. For a spiral phase plate with topological charge 3, fabricated on a resist, optical vortex asymmetry has been shown experimentally by near-field scanning optical microscopy.

• 出版日期2013-2