Different cooling configurations for a high average power longitudinally diode-pumped Yb:YAG amplifier

Area of Science:

• Laser Physics
• Materials Science
• Thermal Engineering

Background:

• Yb:YAG lasers are crucial for various applications.
• Effective thermal management is essential for high-power laser systems.
• Crystal design and cooling significantly impact laser performance.

Purpose of the Study:

• To analyze temperature distribution in Yb:YAG crystals under different cooling configurations.
• To evaluate the impact of crystal design (composite vs. thick) on thermal properties.
• To optimize cooling and crystal design for reduced thermal effects and improved output.

Main Methods:

• Experimental analysis of temperature distribution in Yb:YAG crystals.
• Investigation of composite and thick crystal designs.
• Evaluation of rear-face and rear-and-side cooling configurations.
• Measurement of temperature rise, gradients, crystal bending, and optical phase distortion.

Main Results:

• Different cooling configurations and crystal designs yield varying temperature distributions and thermal deformations.
• A thin, high-doped Yb:YAG sheet (1.6 mm) exhibited significant bending, reducing output energy.
• Optimized configurations balanced average temperature, thermodeformation, and optical phase distortion.

Conclusions:

• Cooling configuration and crystal design are critical for managing thermal effects in Yb:YAG amplifiers.
• Composite crystal designs and optimized cooling can mitigate thermal issues.
• Careful consideration of gain medium thickness is necessary to avoid detrimental bending and energy loss.