Astigmatic Aberration Correction of Slab Laser
Aiming at the problem that the astigmatism component of the slab laser is dominated manly by large-scale astigmatic aberrations, a method for simultaneously correcting defocus, 0°and 45° astigmatism is proposed. The spherical lens, cylindrical lens and adjustment system are employed. Using the theory of ray tracing, the beam divergence angle is used as the intermediate variable to construct a relationship between defocus, 0°astigmatic aberrations and spacing of the two lenses. Further, a mathematical analysis relationship between the 45° astigmatic aberration and the cylindrical lens rotation angle is established, and the correcting rotation angle for 45° astigmatic aberration is directly calculated according to the parameters detected by the wavefront sensor. Then, the experimental results show that the PV value of the incident beam wavefront can be reduced from 30.51μm to 1.5μm, and the beam quality is obviously improved.