Rapid Generation of Light Beams Carrying Orbital Angular Momentum

摘要

We report a technique for encoding both amplitude and phase variations onto alaser beam using a single digital micro-mirror device (DMD). Using thistechnique, we generate Laguerre-Gaussian and vortex orbital-angular-momentum(OAM) modes, along with modes in a set that is mutually unbiased with respectto the OAM basis. Additionally, we have demonstrated rapid switching among thegenerated modes at a speed of 4 kHz, which is much faster than the speedregularly achieved by spatial light modulators (SLMs). The dynamic control ofboth phase and amplitude of a laser beam is an enabling technology forclassical communication and quantum key distribution (QKD) systems that employspatial mode encoding.