Laser beam self-focusing in turbulent dissipative media

Area of Science:

• Optics and Photonics
• Nonlinear Wave Propagation
• Atmospheric Turbulence

Background:

• High-power laser beams propagating through dielectrics are affected by diffraction, dissipation, and optical Kerr nonlinearity.
• Atmospheric turbulence, characterized by Kolmogorov-von Kármán spectral density, introduces random fluctuations affecting laser propagation.
• Understanding these interactions is crucial for applications involving long-distance laser transmission.

Purpose of the Study:

• To analyze the long-term spot radius evolution of a high-power laser beam in a turbulent dielectric medium.
• To investigate the combined effects of diffraction, dissipation, and optical Kerr nonlinearity on laser beam propagation.
• To benchmark theoretical models against experimental data and simulation results.

Main Methods:

• Application of the method of moments to a stochastic, nonlinear enveloped wave equation.
• Modeling atmospheric turbulence using Kolmogorov-von Kármán spectral density.
• Benchmarking against low-power experimental field data and comparison with high-power simulation results.

Main Results:

• Dissipation was found to reduce the impact of self-focusing.
• The study identified chromatic aberration as a consequence of dissipation.
• The method of moments provided an effective analytical approach for long-term spot radius evolution.

Conclusions:

• The interplay between nonlinearity, turbulence, and dissipation significantly influences laser beam characteristics.
• Dissipation plays a critical role in mitigating self-focusing but introduces chromatic aberration.
• The developed analytical method accurately describes long-term laser propagation dynamics in turbulent media.