International audienceWe demonstrate tunable radiofrequency emission from a meter-long linear plasma column produced in air at atmospheric pressure. A short-lived plasma column is initially produced by femtosecond filamentation and subsequently converted into a long-lived discharge column by application of an external high voltage field. Radiofrequency excitation is fed to the plasma by induction and detected remotely as electromagnetic radiation by a classical antenna

International audienceWe describe a simple, sturdy, and reliable spark gap operating with air at atmospheric pressure and able to switch currents in excess of 10 kA with sub-nanosecond jitter. The spark gap is remotely triggered by a femtosecond laser filament