Dynamic control of cylindrical vector beams via anisotropy

Abstract

We demonstrate that the spatially diffractive properties of cylindrical vector beams could be controlled via linear interactions with anisotropic crystals. It is the first time to show experimentally that the diffraction of the vector beams can be either suppressed or enhanced significantly during propagation, depending on the sign of anisotropy. Importantly, it is also possible to create a linear non-spreading and shape-preserving vector beam, by vanishing its diffraction during propagation via strong anisotropy in a crystal. The manageable diffractive effect enables manipulating propagation dynamics of the circular Airy vector beams, i.e., their propagation trajectories can be dynamically controlled by weakening or enhancing self-acceleration of the Airy beam. We further demonstrate that the cylindrical vector beams with initially zero orbital angular momentum can be rotated either clockwise or anticlockwise, relying on the sign of the anisotropy.

Higher-order optical rabi oscillations

“…Here, we have assumed that the vector vortex beam propagates along the axis, which is in accordance with the optical axis. Paraxial coupled wave equations that describe the propagation dynamics of the vectorial light field in the crystal are given by [45] where and denote two Cartesian polarization components of the vectorial field that carries the vector vortex state ; see Eq. 1 .…”

“…Such higher-order light beams are represented by solutions to the Maxwell equations [5] , [6] and can be generated by intracavity [7] or extracavity [8] , [9] , [10] techniques. Since the vector vortex beam displays intriguing correlations between the spin and the orbital angular momentum, studies of spin-orbit interactions of these structured light beams with matter have recently led to the discovery of impressive phenomena [11] , [12] , [13] , [14] , [15] , [16] , [17] , including the conversion of the angular momentum between the spin and the orbit terms [13] , [16] and the spin-orbit optical Hall effect [15] . Thus, vector vortex beams have drawn considerable interest, offering various applications in the context of classical and quantum optics alike [18] , [19] , [20] , [21] , [22] .…”

Vectorial light-matter interaction -- exploring spatially structured complex light fields

“…Crystals that naturally feature such an anisotropy are widely used to fabricate many kinds of polarization optics, including polarizers and wave retarders, and many publications describe the propagation of complex vector beams in anisotropic crystals. [60][61][62][63][64][65][66][67][68][69] Of particular importance for the manipulation of vector light fields are liquid crystals, which form the building blocks of SLMs and q-plates. The spatially varying birefringence of q-plates can be used as an interface to convert between spin and orbital states, for classical beams as well as for individual photons.…”