Abstract

A structured Laguerre–Gaussian (sLG) beam in an optical system with an astigmatic element acquires additional degrees of freedom in the form of changing the fine structure of the beam, its orbital angular momentum (OAM), and topological charge. We have theoretically and experimentally revealed that at a certain ratio between the beam waist radius and the focal length of the cylindrical lens, the beam turns into an astigmatic-invariant one, and such a transition does not depend on the beam radial and azimuthal numbers. Moreover, in the vicinity of the OAM zero, its sharp bursts occur, the magnitude of which significantly exceeds the initial beam OAM and grows rapidly as the radial number increases.

© 2022 Optica Publishing Group

Control of the orbital angular momentum via radial numbers of structured Laguerre–Gaussian beams

A. Volyar, E. Abramochkin, Ya. Akimova, and M. Bretsko
Opt. Lett. 47(10) 2402-2405 (2022)

Fast oscillations of orbital angular momentum and Shannon entropy caused by radial numbers of structured vortex beams

A. Volyar, E. Abramochkin, Ya. Akimova, M. Bretsko, and Yu. Egorov
Appl. Opt. 61(21) 6398-6407 (2022)

Astigmatic laser beams with a large orbital angular momentum

Victor V. Kotlyar, Alexey A. Kovalev, and Alexey P. Porfirev
Opt. Express 26(1) 141-156 (2018)

Measurement of acceleration and orbital angular momentum of Airy beam and Airy-vortex beam by astigmatic transformation

Brijesh Kumar Singh, Roei Remez, Yuval Tsur, and Ady Arie
Opt. Lett. 40(22) 5411-5414 (2015)

Super pulses of orbital angular momentum in fractional-order spiroid vortex beams

A. V. Volyar and Yu. A. Egorov
Opt. Lett. 43(1) 74-77 (2018)