Orbital angular momentum separation in optical vortex array generation with structured light

Abstract

Optical vortices can be generated in a periodic manner across an interference region when three or more plane waves interact, forming a so-called optical vortex array (OVA). In this work, we investigate this novel phenomenon by interfering structured waves instead of plane waves. When a Laguerre-Gaussian beam carrying an orbital angular momentum (OAM) of ±l interferes with two Gaussian beams, we found that the original OAM ±l is separated to l number of vortices, each carrying an OAM of ±1. We present the numerical simulations and experimental verification of this behavior. Our findings provide new insights into the nature of optical vortex.