Abstract

Spiker/sustainer or prepulse-type drivers are required for several kinds of excimer laser excitation. This topology offers increased efficiency and discharge stability and increased electrode life. It does this by initiating or preconditioning the discharge to allow uniform energy loading from a modulator that is electrically matched to the discharge impedance. By matching the driver and discharge impedance, bidirectional current oscillations (after the laser pulse) are greatly decreased or eliminated. We present recent advances at Spectra Technology associated with spiker/sustainer drivers for XeCl and KrF lasers. These advances include multiple parallel ferrite isolation switches and solid state techniques for power conditioning. Use of spike/sustainer techniques with a magnetic isolation switch eliminates the need for a low inductance switch for the full discharge current, thus allowing scaling of excimer lasers to high powers. Solid state switching has the potential for improved lifetime over gaseous discharge-type switches. Recent development of pulse compression and spiker/sustainer circuits has opened the way for development of solid state switched modulators for high power excimer laser use.

© 1989 Optical Society of America