We use a square grid in the Ronchi test. This grid allows processing of both the X and the Y directions when calculating optical path difference. We use trapezoidal integration to analyze the new patterns, since it does not have the smoothing drawback at the edges of the wave front.
© 1998 Optical Society of America
(120.4290) Instrumentation, measurement, and metrology : Nondestructive testing
(120.4800) Instrumentation, measurement, and metrology : Optical standards and testing
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
A. Cordero-Dávila, E. Luna-Aguilar, S. Vázquez-Montiel, S. Zárate-Vázquez, and M. E. Percino-Zacarias, "Ronchi Test with a Square Grid," Appl. Opt. 37, 672-675 (1998)