Abstract

We demonstrate the transfer of information encoded as orbital angular momentum (OAM) states of a light beam. The transmitter and receiver units are based on spatial light modulators, which prepare or measure a laser beam in one of eight pure OAM states. We show that the information encoded in this way is resistant to eavesdropping in the sense that any attempt to sample the beam away from its axis will be subject to an angular restriction and a lateral offset, both of which result in inherent uncertainty in the measurement. This gives an experimental insight into the effects of aperturing and misalignment of the beam on the OAM measurement and demonstrates the uncertainty relationship for OAM.

Keywords

OpticsAngular momentumOrbital angular momentum of lightPhysicsLight beamOrbital angular momentum multiplexingAngular momentum of lightBeam (structure)EavesdroppingOffset (computer science)Free-space optical communicationLaserAngular momentum couplingTotal angular momentum quantum numberComputer scienceClassical mechanics

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Publication Info

Year
2004
Type
article
Volume
12
Issue
22
Pages
5448-5448
Citations
2468
Access
Closed

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Cite This

Graham M. Gibson, Johannes Courtial, Miles J. Padgett et al. (2004). Free-space information transfer using light beams carrying orbital angular momentum. Optics Express , 12 (22) , 5448-5448. https://doi.org/10.1364/opex.12.005448

Identifiers

DOI
10.1364/opex.12.005448