We study the diffraction fields in a hybrid diffractive–gradient-index element composed of an amplitude zone plate and a quarter-pitch Selfoc gradient-index lens under uniform illumination. Focal positions of the diffractive orders and zone-plate diffraction efficiencies are measured, thereby validating the existing theoretical results.
© 2003 Optical Society of America
José Manuel Rivas-Moscoso, Daniel Nieto, Carlos Gómez-Reino, and Carlos R. Fernández-Pousa, "Focusing of light by zone plates in Selfoc gradient-index lenses," Opt. Lett. 28, 2180-2182 (2003)