Transverse orbital angular momentum imparted upon focusing spatiotemporally coupled ultrashort pulses

A simple focusing system such as a lens or a spherical mirror imparts intrinsic transverse orbital angular momentum (OAM) to spatiotemporal (ST) coupled fields with ST covariance, e.g., a tilted pulse. This extremely simplifies the experimental setups used to date to impart transverse OAM. The focused fields with transverse OAM include canonical, elliptical ST vortices and rotating pulses without any ST phase singularity such as the "lighthouse" pulse, whose OAM content has gone unnoticed. Closed-form expressions for these fields in full space and time are provided.