Image Number 3 for United States Patent #7894494.
An apparatus and method which may comprise a seed laser defining an optical cavity producing an output. An amplifier may amplify the seed laser output. A bandwidth error signal generator may provide a bandwidth error signal from measured bandwidth and a target. A bandwidth selection element, which may comprise an adjustable sized aperture external to the cavity of the seed laser may selectively alter the bandwidth of the seed laser output. A bandwidth control system may control the bandwidth control element and also selectively adjust a differential firing time between the seed laser and amplifier or another bandwidth selection actuator to cooperated (coarsely or finely) with the bandwidth selection element to control bandwidth of the laser system.