Development of a high-average-power microsecond erbium-ytterbium-doped fiber laser system

We report a 200 kHz master oscillator power amplifier erbium-ytterbium-doped fiber laser system at a wavelength of 1548.7 nm with a constant pulse energy of-190 mu J providing a tuneable pulse duration of 2 to 5 mu s. The all-fiber laser system consists of a gain-modulated laser diode used as a seeder, two pre-amplifiers, and a booster amplifier. The output power of the laser system after collimation was 38.24 W, with a root mean square instability of 0.19% providing an excellent performance under environmental perturbations. The beam quality factor was estimated to be M2(??????) = 1.08 in the horizontal and M2(??????) = 1.09 in the vertical planes indicating a near-diffraction-limited laser beam. After synchronization to femtosecond pulses, the obtained mu s laser pulses are expected to contribute to novel microprocessing of semiconductors.