Experimental Wavefront Regulation of Adaptive Optics Systems Using Internal-Model Control

This paper presents an experimental internal-model-based output-regulation framework for rejecting static optical aberrations. First, the dynamics of a 140-actuator deformable mirror are identified from experimental input-output data using a subspace identification method.

The identified model is then augmented with an internal model of the disturbance dynamics, and a stabilizing feedback controller is designed for the augmented system. The proposed method is experimentally evaluated on an adaptive optics test bench using controlled Zernike-mode aberrations generated by a second deformable mirror. The closed-loop controller reduces the norm of the measured Zernike wavefront error from 0.7234 to 0.0025 while maintaining the normalized actuator commands within their admissible range.