Planar wavefront aberration measuring method for coherent light source in gitter shear interferometer

摘要

The method employs a pair of diffraction gratings (G1,G2) having identical line geometry. The emergent light wave is split into two divergent components by the grating (G1) which are subject to further diffraction at the grating (G2). This results in an overlapping region and a first interference image for presentation to the CCD camera (EP') via the lenses (L,L2) and zero/even order filter diaphragm. The assembly is then rotated through 90 deg. to provide a second interference image, having an orthogonal relationship, to enable complete reconstruction of the original wavefront aberration.