Sinusoidal gratings made by either the spatial filtering method or holography are used in a Ronchi setup to test lenses and mirrors. The interference between the strong zero-order and two weak first-order wavefronts gives a three-beam Ronchigram in which elliptically shaped moire fringes appear. The ellipses may be used to determine quantitatively the primary aberration, such as the coefficient of spherical aberration, coma, or astigmatism.
© 1990 Optical Society of America
Original Manuscript: November 24, 1987
Published: May 1, 1990
Jenn-An Lin, Jeremy Hsu, and S. G. Shiue, "Quantitative three-beam Ronchi test," Appl. Opt. 29, 1912-1918 (1990)