Abstract: In a laser control system, control circuit, and method, a master oscillator laser generates a seed laser pulse train. An optical modulator receives the pulse train and modulate the pulse train based on a modulation signal to generate modulated seed pulses. A laser amplifier amplifies the modulated seed pulses to generate an amplified pulse sequence output. A control circuit controls the operation of the optical modulator. The control circuit receives a clock signal synchronized with the seed laser pulse train and a trigger input for asynchronous modulation of the seed laser pulse train, generates the modulation signal, and communicates the modulation signal to the optical modulator. The modulation signal controls the optical modulator to selectively transmit and attenuate seed pulses from the seed laser pulse train to produce modulated seed pulses corresponding to the trigger input and attenuated to maintain a predetermined amplitude envelope in the pulse sequence output.