Diode-pumped efficient high-power cascade Tm:GdVO₄ laser simultaneously operating at ∼2 μm and ∼2.3 μm

Area of Science:

• Laser physics
• Solid-state lasers
• Materials science

Background:

• Thulium-doped lasers are crucial for various applications requiring specific wavelengths.
• Developing high-power, efficient Tm-doped lasers, particularly in the 2-3 μm range, remains an active research area.
• Cascade lasers offer a pathway to achieve multi-wavelength or enhanced output power.

Purpose of the Study:

• To report the first efficient, high-power, laser diode (LD)-pumped cascade Tm:GdVO4 laser.
• To investigate simultaneous operation on Tm3+ transitions at ~2 μm and ~2.3 μm.
• To achieve record continuous-wave (CW) output power at ~2.3 μm.

Main Methods:

• Utilizing a cascade Tm:GdVO4 crystal pumped by a laser diode.
• Characterizing the laser output power and slope efficiency for both ~2 μm and ~2.3 μm transitions.
• Optimizing the laser system for maximum CW output.

Main Results:

• The cascade Tm:GdVO4 laser achieved a maximum total CW output power of 8.42 W with a 40% slope efficiency.
• The ~2.3 μm output power reached a maximum of 2.88 W with a 14% slope efficiency.
• This ~2.3 μm output power is the highest reported for LD-CW-pumped ~2.3 μm Tm3+-doped lasers.

Conclusions:

• The developed cascade Tm:GdVO4 laser is highly efficient and capable of high-power output.
• This work establishes a new benchmark for CW ~2.3 μm laser output power in Tm3+-doped systems.
• The results highlight the potential of cascade Tm:GdVO4 lasers for applications requiring ~2.3 μm radiation.