Patent ID: 6272268
Filing Date: 2001-08-07
Classification: G02B

Abstract:
A fiber optic coupler comprising at least first and second fibers,(a) said first fiber having a first-fiber core of maximum refractive index n.sub.11 and a first-fiber cladding of refractive index n.sub.12 surrounding said core, said first fiber having end regions and a tapered coupling region disposed between said end regions,(b) said second fiber having a second-fiber core of maximum refractive index n.sub.21, an inner cladding of refractive index n.sub.22 surrounding said second-fiber core, and an outer cladding of refractive index n.sub.23 surrounding said inner cladding, said second fiber having end regions and a tapered coupling region disposed between such end regions, said coupling regions of said first and second fibers extending side-by-side adjacent one another, and(c) a medium of refractive index n.sub.30 surrounding said coupling regions of said fibers, whereinn.sub.21 >n.sub.22 >n.sub.23 ;n.sub.23.gtoreq.n.sub.30 ; andn.sub.22 >n.sub.12 >n.sub.23.