this invention relates to a method and apparatus by which two series - connected glow discharge devices may be connected to a main power supply without interposing an output switch . the two series - connected glow discharge devices may be used within a single laser or in two different lasers which are pumped simultaneously . both glow discharges may be initiated by a balanced main power supply , a single ended main power supply or a prepulse power supply in conjunction with a main power supply .