High-contrast optical vortex detection using the Talbot effect

Abstract

We apply the near-field Talbot effect to distinguish, characterize, and detect optical vortices. We perform experiments with single-, double-, multiple-slit, and grating diffraction. High-contrast image detection is achieved with the Talbot effect of a grating, even for higher than l=±1 orbital angular momentum states. Furthermore, we manipulate the vortex beam with different vortex states and use the Talbot effect for detecting. The experimental results are supported by theoretical simulations and demonstrate that the Talbot effect provides an excellent tool for optical vortex detection.

Phase Singularities to Polarization Singularities

“…Apertures of different shapes ranging from triangular [81,343], circular [344,345], diamond-shaped [161], hexagonal [346], regular polygon [347], and annular [151,155,348,349] were also used in diffraction experiments. Additional methods for vortex charge determination based on using twisted phase element [350], hyperbolic grating [351], axicon [352], spiral spectra [353], single point detector [354], and Talbot effect [355] were also reported in literature. 10.1.3.…”

Production of orbital angular momentum states of optical vortex beams using a vortex half-wave retarder with double-pass configuration

“…Namely, the left-handed circular polarization (LHCP) produces the vortex with + , while the right-handed circularly polarized (RHCP) light will produce the opposite ( ). The Talbot effect with a diffraction grating ( ) 47 , 55 , together with the use of the grating mask ( ) 49 , made it possible to clearly measure the order and sign of the vortex beam at the same time 26 , 27 . Both are normal binary gratings (200 m period, chromium on glass, Edmund Optics Inc.).…”

“…The intra-cavity method involves production of OAM fields via insertion of some optical components including a spiral phase plate 21 , 22 , a thin opaque disk (a stop) 23 , thin aluminum stripes 24 , or a tilted etalon 25 into the laser resonator to increase the losses of undesired modes. On the other hand, the extra-cavity conversion mean is related to generation of an optical vortex outside the laser cavity using optical elements such as a SLM 26 , 27 , a forked grating 28 , cylindrical lenses 29 , and transmissive programmable metasurfaces 30 . Recently, polarization optics configuration known as a vortex half-wave retarder (VHWR) has been utilized to convert Gaussian laser beams into Laguerre-Gaussian modes with OAM 20 , 31 .…”

“…The Fraunhofer diffraction patterns of vortex beams through special apertures such as a square aperture 43 , a diamond-shaped aperture 44 , an isosceles triangular aperture 45 , a binaural circular aperture 46 were also studied for OAM determination. Another approach is to make use of the near-field diffraction phenomenon known as the Talbot effect 47 to characterize optical vortices and their topological charges 26 , 27 . Two-dimensional Talbot effect of the optical vortices has also been reported 48 .…”

Detection of vortex beams based on mutual interference

“…The detection techniques for vortex beam can be classified mainly into two categories: interference and diffraction. Interference techniques include mainly the Mach-Zehnder interferometer (MZI) [26][27][28] , Sagnac interferometer [29] , Fizeau interferometer [30] , multipoint interferometer [31] , double-slit interferometer [32][33][34] and Talbot interferometer [35,36] , etc. Diffraction techniques usually use devices such as a triangular aperture [37,38] , annular aperture [39,40] , diamond-shaped aperture [41] , single-slit [42] , multi-pinhole plate [43] , gratings [44,45] and metasurfaces [46][47][48] , and so on.…”