Distributed refractive index lens

Abstract

Abstract PURPOSE:To compensate well the spherical aberration and the coma aberration, by forming a plane of incidence and exit of a lens into spherical faces which are convex toward a farther conjugate point of this lens to compensate aberrations by the distribution state of the refractive index and refracting faces as incidence and exit faces. CONSTITUTION:The refractive index distribution of a converging distributed refractive index lens is symmetric about the optical axis and is expressed with an equation n2=n<2>0[1-(gr)<2>+h4(gr)<4>+h6(gr)<6>] (in this equation, n0, (r), (g), and h4 and h6 are the refractive indexes of the center of the lens, the distance from the optical axis in the radial direction, a parameter indicating the degree of a gradient of the refractive index, and coefficients of the 4-degree term and the 6- degree term as high-degree terms of the refractive index distribution respectively). In this lens, coefficients h4 and h6 of high-degree terms of the refractive index distribution satisfy conditions -2.0<h4<0.5 and -5.0<h6<0.3, and the plane incidence and exit of this distributed refractive index lens are formed into spherical faces which are convex toward a farther conjugate point of the lens, thereby compensating well the spherical aberration and the coma aberration.

Inventors

• 👤 Yasuhiro Aono
• 👤 青野　康廣

Bibliographic Details