High-efficiency Yb:YAG laser with a gradient-doped crystal at room temperature

Area of Science:

• Materials Science
• Laser Physics
• Solid-State Lasers

Background:

• Thermal effects in Yb:YAG crystals can limit laser performance.
• Homogeneous doping presents challenges for efficient heat dissipation.

Purpose of the Study:

• To design and demonstrate a gradient-doped Yb:YAG crystal for improved laser performance.
• To investigate the impact of gradient doping on thermal effects and laser efficiency.

Main Methods:

• A Yb:YAG crystal with a gradient dopant concentration (0.11–1.36 at.% Yb3+) was designed.
• Laser performance was evaluated in a single-end pumped configuration using laser diodes.
• Comparison with homogeneous-doped crystals was performed to assess improvements.

Main Results:

• The gradient-doped Yb:YAG crystal showed significantly improved laser performance compared to homogeneous-doped crystals.
• Maximum output power reached 60.2 W with a 53.2% optical-to-optical conversion efficiency.
• A slope efficiency of 61.4% was achieved in continuous-wave operation at 1030 nm.

Conclusions:

• Gradient doping effectively mitigates thermal effects in Yb:YAG crystals.
• The designed gradient-doped Yb:YAG crystal demonstrates excellent gain performance and high-efficiency output.
• This approach is effective for achieving high-efficiency room-temperature laser operation.