An electrical excitation circuit is disclosed for a gas laser. The electrical excitation circuit includes a charging circuit connected in series with a pulse forming network between a power source and the laser load. The charging circuit includes a capacitor charged by the power source and a thyratron for transferring voltage to the pulse forming network. Alternatively, the charging circuit includes a capacitor charged upon the firing of a silicon controlled rectifier through a saturable step-up transformer which saturates for transferring voltage to the pulse forming network. The pulse forming network includes a saturable inductor switch positioned with respect to a capacitor so that when the voltage on the capacitor reaches a predetermined level, saturation of the saturable inductor switch releases electrical energy stored in the capacitor to the laser load.