Diode-pumped high-power 1.9 µm and 2.3 µm cascade Tm:CALGO laser

Area of Science:

• Laser Physics
• Materials Science
• Solid-State Lasers

Background:

• Thulium-doped lasers (Tm:CALGO) are crucial for mid-infrared applications.
• Simultaneous dual-wavelength operation in Tm:CALGO lasers presents unique challenges and opportunities.

Purpose of the Study:

• To investigate simultaneous non-competitive operation of Tm:CALGO laser at 1.9 µm and 2.3 µm.
• To achieve high-power output and analyze the influence of population dynamics on laser performance.

Main Methods:

• Utilized a diode-pumped Tm:CALGO laser system.
• Employed a cascade laser design for simultaneous operation on two Tm3+ transitions.
• Investigated the effect of the 3F4 state population on 2.3 µm laser output.

Main Results:

• Achieved a maximum total continuous wave output power of 6.95 W with 40.3% slope efficiency.
• Generated 4.89 W at 1.9 µm (28.7% slope efficiency) and 2.07 W at 2.3 µm (12.7% slope efficiency).
• Demonstrated a record 2.07 W output power at 2.3 µm for cascade Tm:CALGO lasers.

Conclusions:

• The cascade Tm:CALGO laser design enables efficient simultaneous dual-wavelength operation.
• The study highlights the highest reported 2.3 µm laser power from a cascade Tm:CALGO system.
• First-time demonstration of the impact of 3F4 state population on 2.3 µm laser performance in cascade operation.