For optical alignment, it may be convenient to use a three-dimensional diffraction pattern with zero irradiance along the optical axis. This pattern is created here by using annular screens in the form of a phase daisy, a daisy flower, or a pie, with an even number of slices of an equal central angle and with every other slice with a phase retardation of 180°. We recognize this form of angular variation as a particular solution of a wider set of functions that are able to produce zero axial irradiance.
© 1992 Optical Society of America
Original Manuscript: December 3, 1990
Published: August 1, 1992
Jorge Ojeda-Castañeda, Pedro Andrés, and Manuel Martínez-Corral, "Zero axial irradiance by annular screens with angular variation," Appl. Opt. 31, 4600-4602 (1992)