Patent ID: 6385855
Filing Date: 2002-05-14
Classification: F41G

Abstract:
A sighting device, comprising:a light source; and a fiber optic component, wherein said fiber optic component comprises a core and a cladding, wherein said core is clear, wherein said cladding comprises a fluorescent material which emits fluorescent light upon absorption of ambient light such that at least a portion of said emitted fluorescent light is emitted from a first end of said fiber optic component, wherein said light source is optically coupled to said fiber optic component such that at least a portion of the light emitted from said light source is coupled into said fiber optic component and is emitted from said first end of said fiber optic component, wherein said core has a graded refractive index profile, wherein the refractive index profile of said core is characterized as n&af;(r)={n1&af;[1-2&it;Î”&af;(r/a)g]1/2r&leq;an2r>awhere r is the radial distance from the lens axis, a is the radius of the lens, n1, and n2 are the refractive indices at r=0 and r=a, the parameter g controls the index profile as a function of radius, n1&lE;n2, and 2&Dgr;=(n12âˆ’n22)/n12.