Pulsed laser discharge stabilization

Abstract

Low power discharge preionizers, or species, are provided by a ionizable species generator that preconditions a laser gas to eliminate arcing in lasers, such as pulsed (high repetition rate) lasers. The present invention creates the species in a low power discharge and the species prevents initial arcs from occurring between high voltage electrodes of the laser. The laser comprises a pressure vessel containing the laser gas, a fan for circulating the laser gas, a heat exchanger, a catalyst, and two high voltage discharge electrodes for exciting the laser gas to create lasing. A high voltage power source is coupled to the electrodes for providing a discharge voltage thereto. A primary auxiliary discharge source is disposed adjacent to the electrodes that is used as a preionizer that creates a low density of charged particles in the main discharge volume to act as a uniform seed for the main voltage pulse derived from the electrodes. The ionizable species generator is disposed in the pressure vessel and provides a low power discharge that preconditions the gas to eliminate arcing in the laser. A preionization discharge generated by the ionizable species generator is used to generate species that have low ionization potential. These easily ionized species are then preionized by ultraviolet radiation generated from the primary auxiliary discharge adjacent to the main discharge electrodes to form a uniformly ionized background for the main discharge to work on. The low ionization potential species replace the gas hydrocarbon contaminants that are adsorbed by the catalyst. A method of eliminating arcing in the laser is also disclosed.