An apparatus for providing power to a gas discharge lamp comprises a storage capacitor and an ignition switch coupled through a primarily parasitic first inductor to a parallel combination of a diode assembly and a second inductor in series with a gas discharge lamp. The second inductor is selected to optimize the energy transfer from the capacitor to the gas discharge lamp. During a first interval determined by the time constant of the series combination of a storage capacitor, a first inductor, and a second inductor, the diode assembly is not conducting and a forward sense current builds in the first and second inductors. During a second interval determined by the interaction of the two parallel circuits driving the gas discharge lamp, during which the diode array is conducting, the smaller reversed sense current flowing in the first inductor and a larger forward sense current flowing in the second inductor add, thereby generating a unipolar, forward sense, single pulse current output for the generation of optical energy by a gas discharge lamp.