Diffraction properties of light with transverse orbital angular momentum

Abstract

The spatiotemporal optical vortex (STOV) is unique, owing to its phase singularity in the space–time domain, and it can carry transverse orbital angular momentum (OAM). Diffraction is a fundamental wave phenomenon that is well known for conventional light; however, studies on the diffraction of light with transverse OAM are limited. Furthermore, methods that enable the fast detection of STOVs are lacking. Here, we theoretically and experimentally study the diffraction behaviors of STOVs, which are different from those of conventional light. The diffraction patterns of STOV pulses that are diffracted by a grating exhibit multilobe structures with a gap number that corresponds to the topological charge. The diffraction rules of STOVs are also revealed. An approach for the fast detection of STOVs is provided using their special diffraction properties. This method has potential applications in fields that require fast STOV recognition, such as STOV-based optical communications.