InGaN diode pumped actively Q-switched intracavity frequency doubling Pr:LiYF₄ 261  nm laser

Abstract

We demonstrate actively Q-switched deep ultraviolet laser operation at 261 and 320 nm by intracavity frequency doubling of an InGaN laser diode-pumped Pr:LiYF₄ laser. We obtain a maximum peak power of 61.6 W (8.7 μJ/pulse at 7.7 kHz) and 594 W (19.0 μJ/pulse at 7.7 kHz) with a pulse width of 142 and 35 ns at 261 and 320 nm, respectively. The conversion efficiency from the fundamental laser energy at 639 nm to the second-harmonic generation is 88%. Good agreement is obtained with prediction by a rate equation model.

Blue LD-pumped electro-optically Q-switched Pr:YLF visible laser with kilowatt-level peak power

“…The results demonstrate the great potential of EO Q-switched visible laser to generate high energy laser pulses. The pulse width in this work was inferior to Co:MALO [14,15] and AO Q-switcher [16,17], but it was shorter than other passively Q-switched lasers in Table 1. In our work, the pulse width behaved an obvious shorten tendency with the increase in pump power, and we did not find any optical damage on the KD*P crystal.…”

“…In contrast, the actively Q-switched techniques not only provide more stable modulation frequency but also have higher damage threshold than SAs. Kannari et al [16] successfully realized the Pr:YLF pulsed lasers using the acousto-optic (AO) Q-switcher at visible band in 2014. In their work, the highest pulse energy was 3.3 μJ at 522 nm and 27 μJ at 639 nm, and the corresponding pulse width was 32 ns and 17 ns, respectively.…”

Actively Q-switched Tb:LiYF4 green lasers

“…60%) and employing more powerful pump sources in the future. In addition, this result is much better than that obtained with the similar AO-Q-switched Pr:LiYF 4 green laser (pumped at 444 nm and emitted at 522 nm, linear cavity) reported in, 25) which was around 1% in terms of absorbed pump power at 7.7 kHz (pulse energy of 3.3 μJ and absorbed pump power of 2.4 W). Further, several tendencies can be observed from Fig.…”

1 kW Peak Power Self-Frequency-Doubling Microchip Laser

“…The first one is the direct emission and modulation in the green spectral range. Passive or active modulators were inserted into the blue laser pumped Pr 3+ , Sm 3+ , Tb 3+ , Dy 3+ , Ho 3+ and Er 3+ lasers [4]- [6], and pulsed 522 nm lasers were successfully demonstrated based on Pr 3+ :GdLiF 4 and Pr 3+ :YLiF 4 crystals [7], [8]. The main obstacle of this method is the lack of suitable modulator which responses at the green spectral range.…”