63 W wing-pumped Tm:YAG single-crystal fiber laser

Area of Science:

• Laser Physics
• Materials Science
• Photonics

Background:

• Thulium-doped Yttrium Aluminum Garnet (Tm:YAG) lasers are crucial for generating light in the 2 µm spectral range.
• Single-crystal fiber (SCF) lasers offer advantages in thermal management and beam quality compared to traditional bulk lasers.

Purpose of the Study:

• To develop a high-power continuous-wave (CW) Tm:YAG SCF laser.
• To investigate the performance of a wing-pumping scheme for Tm:YAG SCF lasers.
• To achieve power scalability in the 2 µm spectral range.

Main Methods:

• Utilized a Tm:YAG single-crystal fiber laser architecture.
• Employed a wing-pumping scheme with laser diodes operating at 791 nm.
• Incorporated diffusion-bonded undoped YAG end caps for enhanced thermal management.

Main Results:

• Achieved a maximum CW output power of 63.3 W at approximately 2.01 µm.
• Recorded a slope efficiency of 34.2%.
• Demonstrated the highest power reported for a Tm:YAG SCF laser in the 2 µm spectral range.

Conclusions:

• The wing-pumping scheme is effective for high-power Tm:YAG SCF laser operation.
• The fiber geometry and diffusion-bonded end caps contribute to uniform pump intensity and thermal load distribution.
• This work advances power scalability for Tm:YAG SCF lasers in the 2 µm range.