Patent ID: 6934443
Filing Date: 2005-08-23
Classification: G02B

Abstract:
1. An optical fiber coupling system for optically coupling an end surface of a silica-based optical fiber for communication and another optical element to each other with reduced back reflectance, comprising: a conical protrusion of a core portion of said optical fiber protruded from a clad portion of said optical fiber at an end portion of said optical fiber, said conical protrusion having a side surface inclined so as to be tapered toward a forward end, said side surface being in contact with a surrounding medium, wherein back reflectance in said silica-based optical fiber is reduced by said surrounding medium which is in contact with said side surface of said core portion at said end portion of said optical fiber having a refractive index of 1.35 to 1.60; and said forward end of said core portion at said end portion of said optical fiber being shaped like a truncated cone; and an area of a top surface of said truncated cone being not larger than ⅕ as large as an area of a bottom surface of said truncated cone.