Wavefront sensor design based on a micro- mirror array for a high dynamic range measurement at a high lateral resolution

The proposed wavefront sensor design based on a digital micro-mirror array (DMD) promises to give a high lateral resolution at a high dynamic range. But there are specific challenges as the diffraction effects caused by the small dimensions of the array and the angular stability of the signal which will be addressed in this paper. The diffraction effects that result from the small structures of the DMD can be reduced by the use of an appropriate wavelength. Besides the consideration of the diffraction effects another important characteristic when using a DMD in the proposed set-up is the stability of the tilt angle of the mirrors. In order to determine the angular stability of the signal a high resolution measurement of a signal of 3 x 3 mirrors was conducted. The angular stability of the signal snowed to be applicable for a high resolution wavefront measurement. Future work will mainly address the specific challenges that result from the possible high measurement range of up to 10 deg., such as errors that might be generated in the imaging telescope or in the focusing optic at higher field angles.