Spatiotemporal evolution of focused single-cycle electromagnetic pulses

tal seems to correspond to conical emission already observed in solid or gas. Our measurements show that the conical emission only takes place in the very first part of the filament path, which explains the well-defined shape of the conical rings observed outside the sample. The stable 3D propagation ofthe filament cannot be explained in the frame of the nonlinear Schrodinger equation and ionization plays a important role in the physics of the filament. Measurements, including 3D mapping of the filament, made on samples with different ionization and electronic recombination rates or time constants will be presented to give more insight and try to understand the filament propagation that potentially has very important applications.