The horizontal propagation steady-state thermal blooming effects of laser beams with different intensity distributions, such as Gaussian beam, flat-top beam, and flat-top beam with center obscuration, have been investigated by numerical simulation. The impacts of the output power, the propagation distance, the beam diameter, and the wind velocity vertical to the propagation direction on the steady-state thermal blooming have been discussed for the above mentioned three kinds of beams. Furthermore, the steady-state thermal blooming induced Strehl ratio degradation and peak intensity offset versus the generalized thermal distortion parameter N after long-path horizontal propagation of laser beams with above mentioned three types of intensity distributions have been derived. The simulation results show that, for certain other parameters, the greater output power or longer propagation distance will induce the stronger thermal blooming, and the increment of the launch diameter or the convection wind velocity vertical to the propagation direction will weaken the thermal blooming oppositely. Furthermore, for laser beams with different intensity distributions, the impacts of the thermal blooming on the propagation are so different. Under the same generalized thermal distortion parameter N, the thermal blooming effect on the Gaussian beam is the most serious, followed by the flat-top beam, and flat-top beam with center obscuration is the smallest.
Numerical simulation of horizontal propagation steady-state thermal blooming effect on laser beam with different intensity distribution
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Get Citation: Wu S Y, Li X Y, Luo X. Numerical simulation of horizontal propagation steady-state thermal blooming effect on laser beam with different intensity distribution[J]. Opto-Electronic Engineering, 2018, 45(2): 170620.