Patent ID: 7885308

Claim:
A gas discharge laser, comprising: a laser housing including a laser gas and an electrode-assembly for lighting a discharge in the laser gas, the electrode assembly having a first resonant frequency when the discharge is not lit, and a second resonant frequency when the discharge is lit; and electronic circuitry arranged to optimize at least the first resonant frequency, wherein the electronic circuitry optimizes the first resonant frequency by causing multiple RF pulses having a duration insufficient to light the discharge at a plurality of different frequencies within the frequency-range of the source while detecting the reflected RF power, and recording the frequency for which the detected reflected power is at a minimum value as the optimized first resonant frequency, the electronic circuitry further arranged to apply RF power to the electrodes at the optimized first resonant frequency for a first predetermined pulse width insufficient to light a discharge in the laser gas but sufficient to create sufficient free electrons in the gas to facilitate lighting of the discharge, and thereafter light the discharge by applying RF power to the electrodes at the second resonant frequency.