Compact snapshot freefrom null testing with adaptive optics (Conference Presentation)

Abstract

We present a snapshot, adaptive null interferometric system for measuring freeform surfaces using deformable mirror as the null corrector to increase the measurement range. To compensate the wavefront for different surfaces, a computer controlled deformable mirror is used as an adaptive wavefront corrector. A deformable mirror control algorithm based on stochastic parallel gradient descent algorithm has been developed to drive the deformable mirror to null the interference fringe. Snapshot phase measurement is proposed in the optimization progress to increase the iterative speed. The surface shape of the deformable mirror is measured by a deflectometry system to calculate the shape of the surface under test.