Detecting wavefront amplitude and phase using linear phase diversity.

We propose a simplified phase diversity method based on the first-order Taylor expansion of the optical transfer function (OTF) as the light intensity on the pupil plane is not uniform but presents Gaussian distribution. By extending the Zernike polynomial term to the complex field, we regard the distribution of the light intensity as the imaginary part of the phase, which can be solved together with the phase aberration (the real part of the phase). The approximation of the OTF using the first-order Taylor expansion can simplify the relationship between the phase and OTF to linear relation, so that the aberration can be quickly solved. We present an experiment that validates the advantage of our method. The result shows that the modified method has a higher accuracy with less time compared to the traditional phase diversity algorithm, and can acquire the distribution of the light on the pupil plane.