Angular lens

We propose a single phase-only optical element that transforms different orbital angular momentum (OAM) modes into localized spots at separated angular positions on a transverse plane.We refer to this element as angular lens since it separates out OAM modes in a manner analogous to how a converging lens separates out transverse wave-vector modes at the focal plane.We also simulate the proposed angular lens using a spatial light modulator and experimentally demonstrate its working.Our work can have important implications for OAM-based classical and quantum communication applications.