Laser beam shaping using a novel intra-cavity adaptive optical system

Many high power lasers typically suffer from reduced beam quality due to thermally induced aberrations. Adaptive optics is an effective way to compensate the dynamic aberration. But adaptive optics has not found widespread acceptance due to the cost and complexity. It is not until recently that can the problem be readily solved with the development of microelectromechanical systems (MEMS) based on silicon micromaching technology. Calculations are performed showing the effect of Zernike aberrations on laser beam quality. We describe an intra-cavity adaptive optical system based on a MEMS deformable mirror to compensate the thermally induced aberrations. The experimental result showed that the output power was increased nearly 3 times and the beam quality was improved obviously by closed loop automatic control of the adaptive optical system.