Role of symmetry in self-healing of singular beams

• Published in: Applied physics. B, Lasers and optics Vol. 129; no. 2
• Main Authors: Komal, Baby, Arora, Gauri, kumar, Sunil, Senthilkumaran, P.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.02.2023; Springer Nature B.V
• Subjects: Applied physics; Asymmetry; Engineering; Fields (mathematics); Helicity; Lasers; Obstructions; Optical Devices; Optics; Perturbation; Phase distribution; Photonics; Physical Chemistry; Physics; Physics and Astronomy; Quantum Optics; Singularities; Stokes parameters; Symmetry; Wave fronts; Wave propagation
• ISSN: 0946-2171; 1432-0649
• DOI: 10.1007/s00340-023-07978-0

The phase discontinuities in the wavefront smooth out during propagation. This smoothing out phenomenon by diffraction in some cases leads to healing of the wavefront thereby restoring the original field distribution, even when the wavefront is subjected to obstructions. We, for the first time, report that the symmetry of the obstruction plays a crucial role in the healing process of an optical beam. Singular beams are seen to heal on facing an obstruction that is symmetric about the optical axis of the beam. It is found that scalar, as well as vector vortices, do not heal under asymmetric (non-symmetric) perturbations. Vector field singularities (V-points) split into multiple ellipse-field singularities (C-points) under asymmetric obstructions based on the index, and helicity conservation rules. Stokes parameter S 3 and Stokes phase distributions ( Φ 12 ) are also examined to observe the split of V-points into C-points clearly. The perturbation of the V-points with asymmetric obstacles can be used as a generation technique for producing C-points from V-points. All the above claims are well supported in the article with the appropriate experimental results