Experimental approach to the characterization of a micro-machined continuous-membrane deformable mirror

The purpose of this study was the experimental determination of the type of wave aberration corrected by the micro-machined continuous-membrane deformable mirror from OKO Technologies, and the determination of the limitation in the dynamic range of its correction. We wanted to compare these characteristics with the requirements met in vision science and we wanted to be able to judge the capacity and performance of this deformable mirror for this field of application. To characterize the quality of the static aberration correction of the system, we used phase plates simulating astigmatism and higher order aberrations for an artificial eye consisting of a lens and an USAF resolution target. The pupil size used for the scanning area was 6 mm. The adaptive optics system worked as a closed-loop. Our methodology consisted of measuring the aberrations of these plates and subsequently comparing them with the exact specification given by the manufacturer. In a second time, we corrected the wave front and analyze the quality of the correction by comparing the total root mean square wave front error and the Strehl ratio before and after compensation. We also studied the speed of convergence of the system. We then compared the experimental results with the theoretical simulations of the mirror behavior from other publications.