Practical application of the geometric wavefront sensor for adaptive optics

Wavefront sensors measure specific properties, either in the optical pupil plane or indirectly at the image plane; the former uses incident light in the pupil of an optical system, whereas the later employs one or more focal plane sensors to recover the wavefront. Phase perturbations, in the form of low-order Zernike coefficients, e.g., defocus (Z(5)) in this case, are introduced using a bimorph deformable mirror. We investigate the practical application of the geometric wavefront sensor (WFS), using a versatile optical test-bench to emulate the effects of wavefront propagation in an open-loop configuration. In this paper, the estimation of residual wavefront error, for a user-generated aberration, is further verified using simulation results.