Patent ID: 6535679
Filing Date: 2003-03-18
Classification: C03B,G02B,Y02P

Abstract:
An optical fiber containing silica glass, comprising:a first core having a predetermined refractive index; a second core around an outer periphery of said first core and having a refractive index lower than that of said first core and an outer diameter of 25-40 &mgr;m; a first cladding around an outer periphery of said second core and having a refractive index lower than that of said second core; and a second cladding around an outer periphery of said first cladding and having a refractive index higher than that of said first cladding and lower than that of said second core; wherein: said first core comprises a glass region containing at least germanium dioxide; said second core comprises a glass region which is not doped with germanium dioxide and is not doped with fluorine; said first cladding comprises a glass region containing at least fluorine; and said second cladding comprises a glass region containing fluorine.