The generation of arbitrary vector beams using a division of a wavefront-based setup

Abstract

In this paper, we introduce an arbitrary vector-beam-forming scheme using a simple arrangement involving only one liquid crystal spatial light modulator. An arbitrary vector beam can be obtained by overlapping two orthogonally polarized beams. In most of the existing vector-beam-forming schemes the two orthogonally polarized beams are essentially copies of a single incident wavefront. However, in the proposed scheme the two orthogonally polarized beams correspond to two separated parts of a single incident wavefront. Taking a cue from the two-beam interference phenomenon, the present scheme can be referred to as a division of a wavefront-based scheme. The proposed setup offers certain important advantages and is more suitable for the generation of higher average-power vector beams. We demonstrate the working of the vector-beam-forming scheme by generating various vector beams such as radially polarized, azimuthally polarized, and Bessel–Gauss beams and also a boat-shaped beam in the focal volume of a low-numerical-aperture focusing lens. The boat-shaped beam comprises a dark center surrounded by intense light from all but one direction. The beam is realized at the focus of an azimuthally polarized beam in the presence of a moderate amount of coma in the beam. The experimental results obtained using the proposed setup are verified by comparing them with the theoretical results.