A gradial zone lens has the diffractive component within the bulk lens rather than as a surface-relief profile. It is constructed by spin molding annular zones from microliter volumes of monomers injected into a rotating mold. Plastic lenses have micrometer width zones with dimensions that give a phase difference of modulo 2π. A gradial lens made with flat surfaces shows a series of foci similar to those of a radially blazed grating; however, when zones are placed within a plano–convex lens, there is an additive contribution from both refractive and diffractive focusing.
© 1994 Optical Society of America
Original Manuscript: May 13, 1994
Published: November 1, 1994
David P. Hamblen, "Diffractive optics: the gradial zone lens," Opt. Lett. 19, 1687-1689 (1994)