Numerical simulation of time-dependent thermal blooming

摘要

In this study, the time-dependent thermal blooming is studied by numerical simulation. The numerical simulation shows the rules of the far-field spot of the focused Gaussian beam as time progresses. In order to evaluate the effect of time-dependent thermal blooming on the quality of the laser beam, far-field spot peak intensity offset Ax/a, radius of encircling 83.8% energy and peak Strehl ratio S_r calculations can be used to measure system performance as a function of time. At this time, the thermal distortion parameter N are 9.433, 18.866 and 37.732, respectively. The results show that, with the evolution of time, the quality of the laser beam affected by the thermal blooming will be degraded, which is manifested by the deflection of the beam, the far-field spot will be continuously expanded, and the peak Strehl ratio will be decreased, but eventually the spot pattern will be stable.