Abstract
We investigated performances of triggered and guided discharges in a 1-m long gap with negative and positive voltages using femtosecond-terawatt-laser-induced plasma filaments. Discharge guiding mainly occurred from the negative electrode in both cases of negative and positive discharges. Photos taken when a breakdown didn't occur show that a leader generated from the negative electrode and that from a laser-induced plasma filament combined each other. Laser-induced breakdown occurred even when the high voltage electrode was separated from the laser beam by up to 10 cm. These experiments also show that the breakdown induced by the plasma filament needs a certain guide length.
