Simple and compact high-power continuous-wave deep ultraviolet source at 261 nm based on diode-pumped intra-cavity frequency doubled Pr:LiYF4 green laser

Compact high-power 320-nm continuous-wave single-frequency laser based on power scaling of a diode-pumped Pr:LiYF4 ring laser at red

Single-frequency (SF) lasers in the visible spectral region are usually obtained through an indirect method, i.e., frequency doubling of near-infrared SF lasers. In this work, we report on the direct generation of a high-power continuous-wave (CW) SF laser in red based on a diode-pumped Pr:LiYF4 (YLF) ring cavity technology. A maximum output power is scaled to 3.98 W at 640 nm with a linewidth of about 17.2 MHz and a power stability of 0.6%. Moreover, by inserting a LBO crystal into the ring cavity for intracavity frequency doubling of the 640 nm SF laser, we have also successfully demonstrated an ultraviolet (UV) SF laser at 320 nm, for the first time to the best of our knowledge, with a maximum power of 670 mW. This work provides a promising route for the development of simple, compact, and high-power SF lasers operating in visible and UV spectral regions.

7.56-W continuous-wave Pr3+-based green laser via managing thermally induced effects

Blue-laser-diode-pumped Pr3+-based continuous-wave (CW) green lasers have aroused growing research interest in developing optoelectronic applications and deep ultraviolet laser sources due to their simple and compact structural design. However, the obstacle of thermally induced effects limits the available output power of Pr3+-based green lasers. Herein, combined with the theoretical analysis and experimental feedback, we effectively adjust the heat distribution inside the Pr3+:LiYF4 gain crystal by optimizing the crystal dimension and doping concentration. The excellent mode matching between the pump and green lasers is achieved under the consideration of thermally induced effects, yielding a maximum CW output power of 7.56 W. To the best of our knowledge, this is the largest output power of Pr3+-based CW green lasers so far. Moreover, the obtained green laser demonstrates excellent output stability (RMS = 1.27%) and beam quality (M2 = 1.30 × 1.12) under the lasing operation state with the maximum output power. We hope that this study can provide a feasible paradigm for developing blue-laser-diode-pumped visible lasers, especially for high-power lasers.