Analysis of beam deviation induced by thermal blooming effect when high-energy laser propagating up in atmosphere

Abstract

Based on the thermal blooming effect theory for high-energy laser propagating in atmosphere, the vector model concept of thermal distortion parameter <inline-formula><tex-math id="M1">\begin{document}$ {{\boldsymbol{N}}_{\text{D}}} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="24-20211138_M1.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="24-20211138_M1.png"/></alternatives></inline-formula> is put forward. Based on the vector model concept of thermal distortion parameter and the laser system simulation software EasyLaser, the scaling law between the centroid offset of laser beam farfield and the vector thermal distortion parameter is simulated and analyzed. The simulation results indicate that the centroid offset quantity is in direct proportion to the modulus of vector thermal distortion parameter <inline-formula><tex-math id="M2">\begin{document}$ {{\boldsymbol{N}}_{\text{D}}} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="24-20211138_M2.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="24-20211138_M2.png"/></alternatives></inline-formula>, and the centroid offset direction is opposite to the direction of vector thermal distortion parameter <inline-formula><tex-math id="M3">\begin{document}$ {{\boldsymbol{N}}_{\text{D}}} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="24-20211138_M3.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="24-20211138_M3.png"/></alternatives></inline-formula>. Based on the scaling law, by real-time measuring the atmosphreic parameters on laser beam propagation path, the beam deviation of laser system can be conveniently estimated in practical application.

Multiparameter Influence Analysis of the Target Spot Power Distribution of Airborne Laser

“…The 𝐶 𝑛 2 in the Fried parameter 𝑟 0 of atmospheric turbulence and the Vmind parameter in the thermal distortion parameter 𝑁 𝐷 are related to the altitude. Easylaser uses the phase screen to simulate the atmosphere [30], [31]. The wind speed and direction for each layer of the phase screen are different.…”

Uncertainty analysis of propagation efficiency of high-energy laser horizontal propagation in the atmosphere

“…The high energy lasers propagating in the atmosphere interact with the atmospheric medium and suffer from a series of linear and nonlinear effects, leading to the spreading and wandering of laser beams [1][2][3][4] . These atmosphere effects are closely related to the laser system, atmospheric optical characteristics and propagating geometry 5 .…”

Study on phase change of Gaussian beam induced by thermal blooming effect

“…In recent years, Ji and et al have theoretically studied the thermal blooming effect of laser beams propagating through the atmosphere [13,14] and seawater [15] . Zhang and et al have numerically analyzed the beam deviation induced by thermal blooming effect when high-energy laser propagating upwards in the atmosphere [16] . In 2021, Lu and et al experimentally investigated the thermal blooming induced phase change and its compensation of a Gaussian beam propagation in an absorbing medium [17] .…”