The most common approach to create orbital angular momentum (OAM) carrying vortex beams is by modulating a Gaussian beam with an azimuthal phase profile. This results in a beam with many radial modes and hence reduced power in the desired mode. Here we show that it is possible to select the mode size of the Laguerre-Gaussian basis so that the power in the detected p = 0 mode is maximised. We outline the idea theoretically and confirm it experimentally with both classical and quantum tests, demonstrating a power increase by as much as 50x. The consequence is higher signal-to- noise in optical communication and larger available dimensions in quantum entanglement experiments when using OAM modes as a basis.

Date Published: 10 September 2019
PDF
Proc. SPIE 11134, Quantum Communications and Quantum Imaging XVII, 111340T (10 September 2019); doi: 10.1117/12.2530009

Published in SPIE Proceedings Vol. 11134:
Quantum Communications and Quantum Imaging XVII
Keith S. Deacon, Editor(s)