Patent ID: 6427044
Filing Date: 2002-07-30
Classification: C03B,C03C,G02B

Abstract:
An optical fiber comprising:a core region whose maximum value &Dgr;max of relative refractive index difference with respect to silica glass non-intentionally doped with impurities is 0.8% or more, in its diameter direction; a cladding region provided on the outer periphery of said core region and comprised of silica glass non-intentionally doped with impurities; and a hermetic coat provided on the outer periphery of said cladding region and mainly composed of carbon; wherein transmission loss a at a wavelength of 1.55 &mgr;m and said maximum value &Dgr;max satisfy the relationship of: &agr;&lE;0.131Ã—(&Dgr;max)2âˆ’0.214Ã—(&Dgr;max)+0.284.