Miniaturized, high-power diode-pumped, Q-switched Nd:YAG laser oscillator–amplifier

Energy scaling of passively Q-switched lasers In the Mj-range

“…In order to enable a longer energy storage time and therefore to save pump diode peak power Nd:YLF instead of Nd:YAG crystals have been used, which exhibit a fluorescence lifetime of 470µs compared to 230µs for Nd:YAG [1]. For further energy scaling often a master oscillator power amplifier (MOPA) configuration is used [3,6,7]. However, this study focusses on the energy scalability of passively Q-switched low repetition rate oscillators at good beam quality.…”

“…Here, more than 50mJ were achieved at a total pump power of E pump ~240mJ ( opt.-opt =20%). A MOPA design which contains less complexity can be implemented by pumping the oscillator and one amplifier with the same pump diode [7]. In this case, a pulse energy of 8.4mJ at a duration of FWHM=2ns and a beam propagation factor of M²=1.5 was achieved at a pump energy of 160mJ.…”

Nd:YAG single-crystal fiber as high peak power amplifier of pulses below one nanosecond

“…At low repetition rate (10 Hz), 2.7 mJ pulses with a peak power of more than 5 MW have already been generated [1]. The MOPA (Master Oscillator Power Amplifier) configuration can extend the performance and 8.4 mJ pulses have recently been demonstrated [2] with a single pass Nd:YAG amplifier operating at 25 Hz. Those lasers can address applications requiring high energy and high peak power pulses such that ignition of engines or airborne/space borne lidar systems.…”