Tm:YAG single-crystal fiber laser

Area of Science:

• Laser Physics
• Materials Science

Background:

• Thulium (Tm) lasers are crucial for applications requiring 2 µm wavelength emission.
• Developing efficient and robust Tm-doped solid-state lasers remains an active research area.
• Single-crystal fiber (SCF) lasers offer advantages in beam quality and thermal management.

Purpose of the Study:

• To present the first thulium (Tm) single-crystal fiber (SCF) laser utilizing free-space beam propagation.
• To demonstrate enhanced thermal management and pump guiding in the Tm:YAG SCF.
• To achieve high output power and slope efficiency for 2 µm laser applications.

Main Methods:

• Fabrication of a Tm:YAG SCF with diffusion-bonded, undoped YAG end caps.
• Implementation of mode matching and pump guiding strategies within the SCF.
• Characterization of laser output power and slope efficiency at approximately 2.02 µm.

Main Results:

• Achieved a maximum output power of 9.1 W.
• Obtained a slope efficiency of 49.4%.
• Demonstrated successful free-space propagation of the laser beam from the SCF.

Conclusions:

• This novel Tm:YAG SCF laser design offers a straightforward and effective approach for 2 µm generation.
• The use of diffusion-bonded end caps enhances thermal performance and pump delivery.
• The developed laser is suitable for 2 µm amplification stages in various temporal formats.