Lavery Martin P J, Robertson David J, Berkhout Gregorius C G, Love Gordon D, Padgett Miles J, Courtial Johannes
School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, UK.
Opt Express. 2012 Jan 30;20(3):2110-5. doi: 10.1364/OE.20.002110.
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.
我们开发了一种模式变换器，它由两个定制的折射光学元件组成，可将轨道角动量态转换为横向动量态。这种转换使得能够高效测量输入光束的轨道角动量含量。我们对该系统针对50种输入模式的信道容量进行了表征，得到每个光子的最大值为3.46比特。使用电子倍增电荷耦合器件（EMCCD）相机以及经过衰减的激光源，使得在每个测量周期内系统中平均存在的光子数少于一个，我们证明了这些元件在单光子实验中是高效的。
