Nonlinear effects on pulsed laser propagation in the atmosphere

Area of Science:

• Atmospheric optics
• Laser physics
• Nonlinear optics

Background:

• High power laser propagation through the atmosphere is subject to various physical phenomena.
• Understanding these effects is crucial for applications involving long-distance laser transmission.
• Atmospheric turbulence and refractive index variations cause linear effects like beam steering and scintillation.

Purpose of the Study:

• To model nonlinear effects on high power pulsed laser beam propagation in Earth's atmosphere.
• To assess the significance of stimulated Raman scattering and whole beam self-focusing.
• To investigate how wavefront compensation influences the observation of these nonlinear phenomena.

Main Methods:

• Development of a model for nonlinear laser beam propagation.
• Estimation of stimulated Raman scattering for long atmospheric paths.
• Analysis of whole beam self-focusing effects.
• Simulation of laser propagation with and without wavefront compensation.

Main Results:

• Stimulated Raman scattering is significant for modest power lasers over extremely long path lengths.
• Whole beam self-focusing can substantially impact laser beam propagation.
• Wavefront compensation techniques are expected to enhance the observation of nonlinear effects by mitigating linear atmospheric distortions.

Conclusions:

• Nonlinear effects, particularly stimulated Raman scattering and self-focusing, are critical considerations for high power laser propagation in the atmosphere.
• Wavefront compensation is a valuable tool for studying and potentially mitigating these nonlinear phenomena.
• The findings are relevant for both space-to-ground and ground-to-space laser communication and remote sensing applications.