title: Graded-index sphere lens with hemispherical rod cladding.
abstract: When a radially inhomogeneous sphere whose refractive-index profile decreases from center to periphery in a nearly parabolic manner is cladded with an additional hemispherical rod, the spherical aberration of the resultant lens (having a diameter of several millimeters) can be minimized to the diffraction limit for N.A. 0.45.
authors.forename: K
authors.initials: K
authors.lastname: Kikuchi
authors.forename: T
authors.initials: T
authors.lastname: Morikawa
authors.forename: J
authors.initials: J
authors.lastname: Shimada
authors.forename: K
authors.initials: K
authors.lastname: Sakurai