Orbital angular momentum beam diffraction through a dynamic single slit

Abstract

We investigated the single slit diffraction of Laguerre-Gaussian (LG) beams of different topological charges l and derived a relation between the topological charge and the phase difference of the endpoints of the slit. We showed that for odd l there is a central minimum in the diffraction pattern while for even l there is a maximum. Experimentally, we used a digital micromirror device as a dynamic slit and a spatial light modulator to produce the LG beams. Our results show that a dynamic single slit can be used to probe the orbital angular momentum of LG beams.