Patent ID: 8102889

Claim:
A method for controlling bandwidth in a multi-portion laser system comprising an oscillator laser system portion providing a line narrowed seed pulse to a gain generator laser system portion, wherein selection of a differential firing time between the generation of the seed pulse in the oscillator laser system portion and the generation of the laser gain medium in the gain generator laser system portion affects the bandwidth of a laser output light pulse from the multi-portion laser system, the method comprising: adjusting the differential firing time as a function of a measured bandwidth and a bandwidth target; estimating a current operating point by utilizing the difference between a current differential firing time and a reference differential firing time as a function of at least one of the derivative of the laser system output pulse energy with respect to differential firing time at constant voltage (dE/dt) and the laser system output pulse energy (E) at the estimated current operating point, where dE/dt is estimated by applying a dither signal to the differential firing time and taking a respective ratio of the correlations of dither with laser output pulse energy and the actual differential firing time; and limiting the differential firing time adjustment based on the estimated current operating point.