Degeneracy in the diffraction of orbital angular momentum carrying beams.

Symmetry constraints on the far-field diffraction of Laguerre-Gauss vortex beams by planar aperture arrays with N-fold rotational symmetry are considered. The experiments reveal a simple structure for the diffraction pattern and high degree of degeneracy in its dependence on the orbital angular momentum index of the incident beam in agreement with analytical and numerical results.

Polarization properties of Ince-Gaussian laser beams.

A consistent theoretical description of the polarization properties of Ince-Gauss (IG) laser beams is provided by constructing paraxial IG solutions to Maxwell equations. We confirm this description experimentally by recording both the dominant and cross-polarization components. Moreover, by experimentally confirming the evolution of the dominant and cross-polarization components as functions of ellipticity parameters, our paper extends further support to a unified treatment of the three (Laguerre-Gauss, Hermite-Gauss, and IG) families of paraxial laser beams.

Polarization properties of the Airy beam.

Polarization of paraxial Airy beam solutions of Maxwell's equations and its evolution with propagation have been studied. We experimentally demonstrate the existence of the cross-polarization component of the Airy beam, typical of nonplanar phase fronts, and study its evolution with propagation.

Maxwell-Gaussian beams with cylindrical polarization.

It is common practice to work in the approximation that beam-like radiation fields are polarized transverse to the propagation axis. However, even in the paraxial approximation, this fails to correctly describe beam polarization and propagation characteristics. We present here the paraxial Maxwell's equations for beams having cylindrical polarization, which describe the full vector structure of these beams in the paraxial regime. The effect that these relations have on the polarization and propagation of cylindrically polarized Laguerre-Gauss and Bessel-Gauss beams is subsequently explored.

Polarization of orbital angular momentum carrying laser beams.

Polarization of orbital angular momentum (OAM) carrying Laguerre-Gauss optical vortex beams, consistent with Maxwell's equations, is discussed, and experimental evidence for it is presented. The experiments reveal several novel features of such beams, including OAM dependent reconstruction of polarization and spatial profile during propagation.

Cross-polarization of linearly polarized Hermite-Gauss laser beams.

Evolution of transverse intensity profiles for the dominant and cross-polarization components of linearly polarized Hermite-Gauss laser beams is studied experimentally as the beams propagate away from their waist. Measured intensity profiles and their evolution with propagation are in good agreement with the theoretical predictions.

Phase and interference properties of optical vortex beams.

Laguerre-Gauss vortex beams carrying different topological charges are generated from Hermite-Gauss laser beams emitted by a gas laser, and their phase properties are explored by studying their interference with a plane wave. Interference of two Laguerre-Gauss vortex beams carrying equal but opposite topological charge is also studied by using a modified Mach-Zehnder interferometer. Experimentally recorded intensity profiles are in good agreement with the theoretically expected profiles.