Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE
Encoding mutually unbiased bases in orbital angular momentum for quantum key distribution
Angela L. Dudley, Mhlambululi Mafu, Sandeep K. Goyal, Daniel Giovannini, Melanie G. McLaren, Thomas Konrad, Miles J. Padgett, Francesco Petruccione, Norbert Lütkenhaus, Andrew Forbes
Abstract
We encode mutually unbiased bases (MUBs) using the higher-dimensional orbital angular momentum (OAM) degree of freedom and illustrate how these states are encoded on a phase-only spatial light modulator (SLM). We perform ( d - 1)- mutual unbiased measurements in both a classical prepare and measure scheme and on entangled photon pairs for dimensions ranging from d = 2 to 5. The calculated average error rate, mutual information and secret key rate show an increase in information capacity as well as higher generation rates as the dimension increases.