Repetitively pulsed mode-locked Nd:phosphate glass laser oscillator-amplifier system

Performance of a repetitively pulsed mode-locked Nd:glass laser system employing athermal phosphate glass in the oscillator and amplifier stages is described. Improved passive mode-locking characteristics of the oscillator are achieved through use of a l00-microm thick intracavity etalon, enabling reliable generation of transform-limited pulses typically of 5-psec duration. The system produces 1054-nm pulses of high beam quality and ~25-mJ energy at a pulse repetition rate of ~0.2 Hz. Subsequent frequency-doubling steps give conversion efficiencies of ~50% and 25%, respectively.