Chinese Journal of Lasers, Volume. 43, Issue 11, 1105002(2016)
Fatigue Damage Characteristics of Deformable Mirrors for Wavefront Correction
A distorted wavefront to be corrected is built up based on the random phase screen. Then, the stress load spectrum of deformable mirror (DM) in the correction process is obtained by the stress analysis model with finite element analysis method. The fatigue life prediction model is proposed based on stress-cycle (S-N) curve and Miner cumulative damage theory. On this basis, the fatigue damage characteristics of DM for wavefront correction process are analyzed, and the influence of the different driving ways and different structural parameters on the lifetime of DM is discussed in detail. The results indicate that, in the wavefront correcting process, the fatigue damage of rear surface of DM substrate is more serious than that of front surface, and the joints between substrate and poles are most likely to be damaged. For a given shape of the distorted wavefront to be corrected, the fatigue life of DM decreases gradually with the increasing of the peak valley (PV) value of the wavefront. On the other hand, when the PV value of the wavefront is determined, the fatigue life also decreases due to more obviously concentrated stress caused by the increasing high frequency components in the distorted wavefront. Furthermore, the fatigue life can be affected by the structural parameters of DM as well. The life of DM decreases gradually with the increasing of the thickness of substrate, the decreasing of the length of poles and the increasing of the diameter of poles, among which the effects caused by the variation of the diameter of poles are more significant.
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Chen Lixia, Hu Xiaochuan, Zhang Bin, Sun Nianchun. Fatigue Damage Characteristics of Deformable Mirrors for Wavefront Correction[J]. Chinese Journal of Lasers, 2016, 43(11): 1105002
Category: beam transmission and control
Received: Jun. 20, 2016
Accepted: --
Published Online: Nov. 10, 2016
The Author Email: Lixia Chen (chen_lixia2h@163.com)