title: Selfoc microlens with a spherical surface.
abstract: This paper presents the light-focusing properties of a gradient-index rod lens with a spherical end surface which aims at increasing numerical aperture and decreasing lens aberration. Optimum refractive-index profiles for obtaining a smaller focused spot are derived, and the increase of numerical aperture is clarified. Experimental results are described; the Selfoc microlens with a spherical end surface realizes a focused spot below 2 microm in diameter.
authors.affiliation: Nippon Sheet Glass Company, Ltd., Research Laboratory, Konoike, Itami 664, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Yamamoto
authors.forename: H
authors.initials: H
authors.lastname: Nishi
authors.forename: K
authors.initials: K
authors.lastname: Nishizawa
authors.forename: I
authors.initials: I
authors.lastname: Kitano