Higher-order transverse modes of ultrashort isodiffracting pulses - art. no. 046602

We present a family of space-time nonseparable analytic solutions describin g spatiotemporal dynamics of isodiffracting single-cycle and few-cycle puls es,with Hermite-Gaussian and Laguerre-Gaussian transverse profiles. These s olutions are space-time localized wave packets propagating in free space. T he transverse field profile acts as a spatially dependent filter, modifying the pulse spectrum and removing certain frequencies. The consequences of t hose effects in the time domain are the distortions of pulse envelope and t emporal wave form and the creation of "dark pulses" at certain transverse p ositions. In addition, due to the space-time coupling, the instantaneous tr ansverse field pattern changes inside the pulse, as well as with propagatio n distance. These higher-order mode solutions can be used to analyze reflec ted or scattered terahertz pulses, and to understand the wave-form distorti ons of terahertz signals in applications. They are also capable of modeling pulsed fields of phase locking of both transverse and longitudinal modes i n total mode-locked lasers.