Laser operation of highly-doped Tm:LiYF₄ epitaxies: towards thin-disk lasers

Area of Science:

• Materials Science
• Laser Physics
• Solid-State Lasers

Background:

• Thulium-doped lasers are crucial for generating ~1.9 μm radiation.
• Thin-film laser materials require optimized growth and doping for high performance.

Purpose of the Study:

• To demonstrate quasi-continuous-wave laser operation in Tm:LiYF4 thin films.
• To model the laser dynamics, including energy transfer processes.
• To assess the potential of these films for thin-disk laser applications.

Main Methods:

• Growth of 20 at.% Tm:LiYF4 thin films via Liquid Phase Epitaxy (LPE).
• Characterization of laser performance under 793 nm pumping with a double-pass scheme.
• Development of a theoretical model for highly-doped Tm:LiYF4 lasers.

Main Results:

• Achieved quasi-continuous-wave laser operation at 1.91 μm from Tm:LiYF4 thin films (84-240 μm thickness).
• Generated 152 mW average power with a 34.4% slope efficiency.
• Model showed good agreement with experimental data, enabling derivation of energy-transfer parameters.

Conclusions:

• LPE-grown Tm:LiYF4 thin films are suitable for laser applications.
• The developed model accurately describes laser dynamics in highly-doped Tm:LiYF4.
• These thin films are promising for the development of ~1.9 μm thin-disk lasers.