Radial smoothing for improving laser-beam irradiance uniformity

Area of Science:

• Physics
• Optics
• Fusion Energy

Background:

• Laser-beam irradiation uniformity is critical for inertial confinement fusion (ICF) research.
• Achieving uniform energy deposition is essential for igniting fusion targets.

Purpose of the Study:

• To propose and evaluate a novel radial smoothing (RS) approach for enhancing laser-beam uniformity.
• To improve the efficiency and viability of ICF experiments.

Main Methods:

• Implementing a radial smoothing (RS) technique involving fast focal zooming.
• Generating focal zooming via periodical spherical wavefront modulation of the laser beam.
• Utilizing an optical Kerr medium and a pump laser with a Gaussian pulse train for wavefront modulation.

Main Results:

• The radial smoothing approach effectively smoothed speckles in the focal plane.
• Significant improvement in laser-beam uniformity was achieved.
• The RS method demonstrated no obvious negative impact on the high-power laser system's performance.

Conclusions:

• The proposed radial smoothing (RS) method is a viable technique for enhancing laser-beam uniformity in ICF.
• This approach offers a promising solution for overcoming key challenges in fusion research.
• RS contributes to more efficient and stable operation of high-power laser systems for fusion energy development.