  Spatiotemporal optical vortex (STOV) is a unique optical vortex with phase
singularity in the space-time domain and the photons in a STOV can carry
transverse orbital angular momentum (OAM). The STOV shows many fantastic
properties which are worth exploring. Here, we theoretically and experimentally
study the diffraction property of STOV, which is a fundamental wave phenomenon.
The diffraction behaviors of STOVs are obviously affected by the transverse
OAM. The diffraction patterns of STOV pulses diffracted by a grating show
multi-lobe structure with each gap corresponding to 1 topological charge. The
diffraction properties of lights with transverse OAM are demonstrated clearly
and help us understanding the physical properties of STOV, which will be of
special applications, such as the realization of fast detection of STOVs with
different topological charges, which may pay the way for STOV based optical
communication.
