Fringe projection based on Moiré method for measuring aberration of axially symmetric optics

We present a new approach based on a very simple optical interferometric configuration that can be useful for measuring wave front aberrations in optical components having axial symmetry. The optical configuration requires only two mutually coherent plane wave fronts transmitted through or reflected by the optical component under test. The method can be considered as an interferometric fringe projection method. It can also be interpreted also as a reversal shear interferometer. The finite Moiré beating between the interferograms and the CCD array is used to subtract a linear carrier introduced by defocus and tilt making the presence of third order coma and spherical aberrations more evident. Applications of the technique for measuring aberrations of simple biconvex spherical lens and a plano-spherical laser micro-cavity are reported.