Excimer laser pumped by dissociative recombination

A preferred embodiment of an excimer laser has a heat pipe oven adapted to raise sodium therein to a temperature of about 800 Kelvin and thereby vaporize the sodium at a pressure of no more than about 0.1 atmosphere, the heat pipe oven having substantially transparent ends. A ring cavity made up of a plurality of mirrors and an adjustable birefringent filter circulates violet light of a desired wavelength through the transparent ends of the heat pipe oven, and a pump laser introduces radiation into the heat pipe oven at an energy high enough to ionize sodium therein to form Na3+ ions and free electrons. The recombination of Na3+ ions and free electrons causes the ions to dissociate into free sodium atoms and excited Na2 molecules which, when stimulated by violet light of the desired wavelength, further dissociate into two free sodium atoms and emit additional violet light of the desired wavelength.