| Abstract: | The study of nonlinear propagation of ultrashort laser pulses and their potential applications in atmospheric science has garnered significant interest, particularly in weather modification. The focus is on laser-induced filament formation, a dynamic process that occurs when high-power ultrashort laser pulses propagate through a medium like air. Laser filament formation results from the interplay between self-focusing, driven by the Kerr nonlinearity of the medium, and defocusing due to plasma generation [1]. The study emphasizes the critical role of laser parameters, such as beam diameter, pulse duration, and power etc. in this process. Filament formation and propagation are analyzed through solutions of the nonlinear Schrödinger equation (NLSE), accounting for effects such as Kerr self-focusing and ionization. The study also includes predictions from the Marburger equation, an analytical approach estimating the self-focusing distance based on the laser beam's peak power relative to the critical power, providing more insight into the theoretical model in predicting filament formation. Experimentally, a telescope with variable effective focal length, achieved by adjusting the distance between diverging and converging optics, is used to examine filament formation. An analytical approach is used to determine the self-focusing distance, marking the filament onset by varying laser parameters. Filament imaging captures information about filament length under different conditions. By understanding and controlling the nonlinear propagation of ultrashort laser pulses, novel techniques for atmospheric manipulation could emerge, potentially addressing climate-related challenges and enhancing water resource management. This research contributes to the growing field of laser-based atmospheric applications and provides a foundation for future studies on controlled weather modification using ultrashort laser technologies. Additionally, intense ultrashort laser pulses can penetrate clouds with high optical thickness, strong turbulence, or dense fog, further supporting the feasibility of laser filamentation through nonlinear propagation for atmospheric applications [2].
[1] Rodriguez et al. Phys. Rev. E 69, 036607 (2004).
[2] Sun et al. Optics Express 26, 29687–29699 (2018). |
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