We present an algorithm that uses a square grid in a Ronchi test. We assume that the point coordinates of this pattern (termed a bironchigram) are affected by Gaussian errors. To calculate the optical path difference, we apply only one nonlinear least-squares fit to the dot coordinates. The relevant equations are deduced, and experimental results are shown.
© 2001 Optical Society of America
Original Manuscript: November 10, 2000
Revised Manuscript: April 24, 2001
Published: November 1, 2001
Alberto Cordero-Dávila, Juan Manuel Nuñez-Alfonso, Esteban Luna-Aguilar, and Carlos Ignacio Robledo-Sánchez, "Only one fitting for bironchigrams," Appl. Opt. 40, 5600-5609 (2001)