Wavefront correction by a low-cost deformable mirror group in a small-aperture-beam fiber laser

A low-cost deformable mirror (DM) group for wavefront correction in a small-aperture-beam fiber laser is reported in this paper. The DM group consists of nine single-actuator DMs and could act as a "virtual" 9-actuator DM arranged in a 3×3 array. The equivalent distance between two adjacent actuators could reach as small as 3 mm, which can lead to a relatively high lateral resolution. Reflection mirrors in the DM group can be individually polished and high-damage-threshold coated. The unique manufacture flexibility will ensure the particularly low cost of the DM group. In this paper, a detailed configuration of the DM group and its application in small-aperture-beam fiber lasers are presented. Theoretic simulations and experimental results successfully demonstrate its capability in wavefront aberration correction for a small-aperture-beam fiber laser.