Abstract

Detection of photons in orbital angular momentum (OAM) superposition states is crucial to verification of OAM entanglement. In the past this has been realized by laterally shifting a hologram designed to remove a charge 1 phase singularity at its center [1]. Such a laterally shifted hologram converts a beam with an off-center singularity (similar to that created by superposing an m = 0 beam and an m = 1 beam, where m is the OAM mode number) into a Gaussian beam, which is then filtered through a single mode fiber (SMF).

© 2007 IEEE