Geometric Phase and Intensity-Controlled Extrinsic Orbital Angular Momentum of Off-Axis Vortex Beams

Abstract

Smooth control of the intrinsic orbital angular momentum (OAM) carried by a beam of light is important for $e.g.$ optical tweezers, communication, and quantum information processing, while control of extrinsic OAM is useful for $e.g.$ super-resolution microscopy and light-matter interaction with atoms, molecules, and condensates. This study presents a technique to control intrinsic and extrinsic OAM in a single-path configuration that is free from mechanical errors. By managing the relative intensity and Pancharatnam-Berry phase difference between two orthogonal spatial modes with orthogonal polarizations, one may tune the net transverse linear momentum to yield variable extrinsic OAM.