高能固体热容激光器大气热晕效应数值分析

Numerical analysis of thermal blooming in the atmosphere for highenergy solid-state heat capacity lasers

气溶胶粒子从高能激光光束中吸收了能量,通过热传导加热空气,造成空气在光束内形成了温度的不均匀分布,产生对激光波面的影响,从而影响高能激光的传输。对单个和群体气溶胶粒子在单脉冲和多脉冲作用下的行为进行了详细分析;在粒子间距小于高能固体热容激光器的热传导特征半径时,只引起光的散射,而在粒子间距大于高能固体热容激光器的热传导特征半径时,可等效于分子吸收所致热晕。通过数值计算,在一定的简化计算条件下,热晕对高能固体热容激光器大气传输影响不大。

Aerosol particles absorb energy from high-energy laser beam. The air is heated through thermal conduction,which results in the nonuniform distribution of air in the beam and distortion of the laser beam,and finally affect the propagation of high-energy laser. In this paper, the performance of single and multi-particles affected by single pulse and multi-pulses laser were analyzed in detail. When the mean particle spacing was far less than characteristic radius of heat conduction of the solid state heat-capacity laser （SSHCL）, scattering of the beam was caused only by the heating of aerosol particles. On the contrary, when the mean particle spacing was larger than or equal to characteristic radius of heat conduction of SSHCL, the distortion of aerosol-induced thermal blooming could be calculated and equivalent to molecule absorption. The numerical calculation result shows that the thermal blooming hardly influences the propagation of SSHCL beams in atmosphere in certain simplified conditions.