Active Correction Of Intracavity Aberration Combination In Unstable Resonator Thin-Disk Laser

The causes and characteristics of the intracavity aberrations in unstable thin -disk laser arc introduced. And an active correction technique is proposed to correct the aberration in the cavity by the combination of defocused and two-dimensional(2D)deformation mirrors. Based on the simulation and optimization design, the dynamic range of the defocus correction deformation mirror can reaches to 18.52 mu m (peak-valley value). The static surface of the 21) mirror is less than 0.01 mu m (root mean square error), the single driver dynamic range greater than 6 mu m (peakvalley value), and the coupling coefficient is in the range of 30% to 35%. These two kinds of deformable mirrors arc placed in the laser cavity for active closed-loop correction. The beam quality was improved to 19. 5 after defocusing correction, and then improved to 6.5 after 21) deformable mirror correction. The wavefront aberration is reduced from 1.501 mu m ( root mean square error) to 0.185 mu m ( root mean square error). The beam quality increased by 3 times and the root mean square error increased by 8.1 times. Experimental results show that the combined correction mode can effectively improve the intracavity aberration in unstable thin-film laser, and its technical route is feasible.