Sub-nanosecond single-frequency 10-kHz diode-pumped MOPA laser

A single-axial-mode, passively Q-switched (PQS) diode-pumped Nd:YAG laser, generating a diffraction-limited beam train of a parts per thousand 40-60 mu J, similar to 500-ps pulses with adjustable repetition rate in the range 1-10 kHz, was efficiently amplified by a single side-pumped Nd:YVO(4) bounce amplifier. After double-pass amplification, a parts per thousand 1-MW pulse peak power with 577-ps duration and 545-mu J energy was achieved, still maintaining diffraction-limited beam performance. The average output power was 5.45 W at 10 kHz, corresponding to 13% extraction efficiency. The high brightness of this laser system seems ideal for nonlinear optics and some particular laser processing applications.