Theory of a simple and efficient method for the axial optical vortex beam synthesis from a quasi-plane wave

Abstract

The diffraction light field is studied by the numerical calculations of Kirchhoff-Fresnel integral and Fourier analysis. Based on combination of these methods, the condition of an axial optical vortex generation in a quasi-plane wave by the special case of a phase addition in the cross-section of a beam is founded. Amplitude and phase structures of the beam synthesized like a singular one are analyzed using computer simulation. The coefficient of conversion of an axial optical vortex beam from the quasiplane wave is defined by the ratio of intensities and reaches 65 % in the far field diffraction zone. Offered are a simple original technique for the experimental realization of the necessary phase addition to the wave for the axial optical vortex beam synthesis and a light “lock” for trapping the absorbing microparticles by using two inclined mirrors.