Non-collinear interaction of photons with orbital angular momentum

Roger, T., Heitz, J. J.F., Wright, E. M. and Faccio, D. (2013) Non-collinear interaction of photons with orbital angular momentum. Scientific Reports, 3, 3491. (doi: 10.1038/srep03491) (PMID:24336441) (PMCID:PMC3861806)

Abstract

We study the nonlinear interaction between two non-collinear light beams that carry orbital angular momentum (OAM). More specifically, two incident beams interact at an angle in a medium with a second order nonlinearity and thus generate a third, non-collinear beam at the second harmonic frequency that experiences a reduced conversion efficiency in comparison to that expected based on conventional phase-matching theory. This reduction scales with the input beam OAM and, differently from previous spiral bandwidth calculations, is due to a geometric effect whereby the input OAM is projected along the non-collinear interaction direction. The effect is relevant even at small interaction angles and is further complicated at large angles by a non-conservation of the total OAM in the nonlinear interaction. Experiments are performed under different conditions and are in excellent agreement with the theory. Our results have implications beyond the specific case studied here of second-harmonic generation, in particular for parametric down-conversion of photons or in general for phase-matched non-collinear interactions between beams with different OAM.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Faccio, Professor Daniele
• Authors: Roger, T., Heitz, J. J.F., Wright, E. M., and Faccio, D.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Scientific Reports
• Publisher: Nature Publishing Group
• ISSN: 2045-2322
• ISSN (Online): 2045-2322
• Published Online: 13 December 2013
• Copyright Holders: Copyright © 2013 The Authors
• First Published: First published in Scientific Reports 3:3491
• Publisher Policy: Reproduced under a Creative Commons License