52-mJ, kHz-Nd:YAG Laser with Diffraction Limited Output

A High Peak Power and High Beam Quality Sub-Nanosecond Nd:YVO4 Laser System at 1 kHz Repetition Rate without SRS Process

“…A Nd:YAG laser system based on the MOPA approach operating at 300 Hz and using selectable 350-600 ps nominally flat temporal pulse shape has been reported, which generate pulses with 127 mJ energy and maximum peak power of 400 MW [23], but beam quality M 2 were not measured. As is already known, beam quality always gets worse due to thermally induced birefringence in Nd:YAG crystal [21,24]. Laser systems based on end-pumped bulk Nd:YVO 4 crystal have better beam quality because of natural birefringence architecture, which can alleviate thermally induced birefringence [25][26][27].…”

“…However, due to the small volume of the active medium, the pulse energy of a sub-nanosecond laser using bounce geometry is less than 1 mJ. In comparison, Nd 3+ -doped lasers based on bulk crystal may acquire high pulse energy at the kHz level [19][20][21]. A sub-nanosecond single frequency MOPA laser system operating at 500 Hz was reported, which generated pulses with a width of 830 ps, energy of 13 mJ, peak power of 15.7 MW, and M 2 < 1.4 [22].…”