Compact integrated aberration-compensating module for a 9 kW Nd:YAG slab laser based on an off-axis stable-unstable...

Area of Science:

• Laser Physics
• Optical Engineering
• Materials Science

Background:

• High-power slab lasers exhibit complex wavefront aberrations.
• Existing compensation methods are often bulky or complex.
• Accurate aberration correction is crucial for maintaining beam quality.

Purpose of the Study:

• To design and demonstrate an integrated aberration-compensating module (IACM).
• To address the specific wavefront aberrations in a 9 kW Nd:YAG slab laser.
• To achieve compact, robust, and automated aberration correction.

Main Methods:

• Developed an IACM with an adjustable slab-aberration compensator, Shack-Hartmann wavefront sensor, and data processor.
• Measured and analyzed specific wavefront aberrations (asymmetry, large amplitude/gradient, high spatial frequency).
• Experimentally corrected aberrations in a quasi-continuous-wave Nd:YAG slab laser.

Main Results:

• Improved diffraction-limited factor (β) from 20.3 to 3.6 times the diffraction limit (DL) at 9 kW average output power.
• Reduced peak-to-valley aberrations from 9.6 µm to 0.85 µm.
• Reduced root-mean-square aberrations from 2.86 µm to 0.18 µm within five iterations.
• Demonstrated IACM's ability to maintain compensation after power-off.

Conclusions:

• The IACM effectively corrects specific wavefront aberrations in high-power slab lasers.
• The system offers benefits of compactness, robustness, simplicity, automation, and cost-effectiveness.
• Achieved significant improvement in laser beam quality and diffraction-limited performance.