Iterative full-bandwidth wavefront reconstruction from a set of low-tilt Fizeau interferograms for high-numerical-aperture surface characterization

作者：Heil Joachim^*; Bauer Tobias; Sure Thomas; Wesner Joachim

来源：Applied Optics, 2006, 45(18): 4270-4283.

DOI：10.1364/AO.45.004270

Full-bandwidth phase-shifting methods as well as band-limited fringe carrier techniques are both problematic when testing high-NA spherical surfaces in Fizeau interferometers. Phase stepping is usually performed by moving a sample and reference sphere relative to each other along the optical axis. At a high NA the method suffers from phase-shift inhomogeneity across the sample surface. Fringe carrier techniques rely on a minimum fringe frequency and call for an off-axis position of the sample, which in turn introduces condenser aberrations. Distortion of the imaging optics generates further apparent aberrations. We propose to combine both principles. The phase shifts are replaced by a set of very low tilts such that the sample is virtually on axis. Initial wavefront estimates are generated by a fringe carrier method. An adaptive Misell-type algorithm combines the interferometric data and iteratively improves the reconstructed wavefront until full spatial bandwidth is achieved. 0 2006 Optical Society of America.

• 出版日期2006-6-20