Acta Optica Sinica, Volume. 40, Issue 20, 2014001(2020)
Analysis of Spatio-Temporal Characters of Thermal Effects of Optical Components in Laser System
Starting from heat conduction equation and thermal elastic equation, based on EasyLaser simulation software, the temperature distribution and thermal aberration of laser irradiated Si reflective mirror and SiO2 window mirror are simulated and calculated. The spatio-temporal characteristics of temperature rise and thermal aberration of the two elements under the same absorption are compared. The optical-thermal-mechanical control multi-physical coupling simulation are carried out to compare the thermal effect of the laser-irradiated Si mirror and the SiO2 window mirror on the far-field characteristics of laser transmission and the effect of adaptive optics correction. Simulation results show that due to the poor thermal conductivity of the SiO2 window mirror, the thermal aberration linearly increases with the increase of the laser irradiation time, and its distribution is similar to the spatial distribution of the irradiated laser spot, and it still exists for a long time after the laser irradiation is stopped. The Si reflector has good thermal conductivity. The temperature distribution is homogenized in a short time, resulting in a small temperature gradient. The thermal aberration first increases rapidly and then slowly, and the influence of the thermal effect disappears quickly after the laser irradiation is stopped. The spatial distribution of the experimental spot intensity has different effects on the thermal effects of the two components: for the SiO2 window mirror, the high spatial frequency component of the thermal aberration increases, which seriously affects the far-field transmission of the laser beam and the effect of adaptive optics correction, while the Si mirror is hot. The conductivity is large, and the impact is small.
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Peng Hu, Jianzhu Zhang. Analysis of Spatio-Temporal Characters of Thermal Effects of Optical Components in Laser System[J]. Acta Optica Sinica, 2020, 40(20): 2014001
Category: Lasers and Laser Optics
Received: May. 26, 2020
Accepted: Jul. 10, 2020
Published Online: Sep. 30, 2020
The Author Email: Hu Peng (hu_peng@iapcm.ac.cn)