Refractive elements for the measurement of the orbital angular momentum of a single photon

作者：Martin P. J. Lavery, David J. Robertson, Gregorius C. G. Berkhout, Gordon D. Love, Miles J. Padgett, Johannes Courtial · 发表于：Optics Express · 年份：2012 · DOI：10.1364/oe.20.002110 · 被引用次数：279 · 研究领域：Orbital Angular Momentum in Optics、Digital Holography and Microscopy、Optical Polarization and Ellipsometry

We have developed a mode transformer comprising two custom refractive optical elements which convert orbital angular momentum states into transverse momentum states. This transformation allows for an efficient measurement of the orbital angular momentum content of an input light beam. We characterise the channel capacity of the system for 50 input modes, giving a maximum value of 3.46 bits per photon. Using an electron multiplying CCD (EMCCD) camera with a laser source attenuated such that on average there is less than one photon present within the system per measurement period, we demonstrate that the elements are efficient for the use in single photon experiments.