400 W average power Q-switched Yb:YAG thin-disk-laser.

Area of Science:

• Laser Physics
• Materials Science

Background:

• High-power solid-state lasers are crucial for various applications.
• Yb:YAG thin-disk lasers (TDLs) offer excellent thermal management for power scaling.
• Q-switching is a key technique for achieving high peak power pulses.

Purpose of the Study:

• To investigate power scaling of acousto-optically Q-switched Yb:YAG TDLs.
• To explore the effect of output coupler transmittance on laser stability and power extraction.
• To achieve record-breaking average power and pulse energy from this laser system.

Main Methods:

• Theoretical and experimental analysis of laser stability limits.
• Engineering of output coupler transmittance to shift stability borders.
• Operation of an acousto-optically Q-switched Yb:YAG TDL at varying repetition rates and pump powers.
• Numerical simulations to support experimental findings.

Main Results:

• Achieved a maximum average power of 403 W at 12.0 kHz repetition rate with 1220 W pump power.
• Obtained a maximum pulse energy of 57 mJ at 1.00 kHz repetition rate with 520 W pump power.
• Demonstrated stable laser operation at higher repetition rates by optimizing output coupler reflectivity (93%).

Conclusions:

• The study presents the highest average power and pulse energy reported for a Q-switched Yb:YAG TDL.
• Optimizing output coupler transmittance is an effective strategy for power scaling.
• The results pave the way for further advancements in high-power solid-state laser oscillators.