Experimental generation of scalar and vector vortex Pearcey–Gauss beams

Abstract

In this manuscript, we put forward two new types of structured light beams, the vortex Pearcey–Gauss (VPeG) beam, with a homogeneous polarisation distribution, and the vector VPeG (VVPeG) beam, with a non-homogeneous polarisation distribution. The latter is generated as a non-separable superposition of the spatial and polarisation degrees of freedom of light. We achieve their experimental realization through the combination of a spatial light modulator, which creates a scalar Pearcey–Gauss beam, and a q -plate which transforms it into a vortex or a vortex vector beam, depending on its input polarisation state. Their intensity and polarisation distributions along the propagation direction were determined through Stokes polarimetry, which was compared with numerical simulations. As demonstrated, the VVPeG beam evolves from an all-linear polarisation distribution to an approximately full Poincaré beam. The proposed vector beams add to the extensive family of non-separable states of light. We anticipate that both types of beams will find applications in fields as diverse as optical metrology and tweezers, amongst others.

Keywords

• vortex beams
• vector beams
• computer generated holograms
• structured light
• beam propagation