摘要:
A co-doped optical fiber is provided having an attenuation of less than about 0.17 dB/km at a wavelength of 1550 nm. The fiber includes a core in the fiber having a graded refractive index profile with an alpha of greater than 5. The fiber also includes a cladding in the fiber that surrounds the core addition, the core includes silica that is co-doped with two or more halogens, for example chlorine and fluorine, the concentration of the two halogens within the core being non-uniform. A method of making a core cane comprising doping a soot body with chlorine and/or bromine and then doping the doped soot body with fluorine is also provided.
摘要:
A process and an apparatus for drying and consolidating an optical fibre preform in a furnace tube comprising a heating chamber, wherein an extension tube having an extension chamber configured to house at least a length portion of the preform is removably joined to the furnace tube and the drying process starts with the preform not completely inserted into the furnace tube, an upper length portion of the preform being surrounded by the extension tube joint to the furnace tube.
摘要:
An optical fiber with low attenuation and methods of making same are disclosed. The optical fiber has a core, an inner cladding surround the core, and an outer cladding surrounding the inner cladding. The outer cladding is chlorine-doped such that the relative refractive index varies as a function of radius. The radially varying relative refractive index profile of the outer cladding reduces excess stress in the core and inner cladding, which helps lower fiber attenuation while also reducing macrobend and microbend loss. A process of fabricating the optical fiber includes doping an overclad soot layer of a soot preform with chlorine and then removing a portion of the chlorine dopant from an outermost region of the overclad soot layer. The soot preform with the modified chlorine dopant profile is then sintered to form a glass preform, which can then be used for drawing the optical fiber.
摘要:
A method of making a multi-mode optical fiber that includes: depositing a porous germania-doped silica soot to form a germania-doped porous soot preform; optionally depositing a porous silica layer over the porous soot preform; doping the porous soot preform and the optional porous silica layer with a fluorine dopant to form a co-doped soot preform having a core region and a fluorine-doped (optionally trench) region; consolidating the co-doped soot preform to form a sintered glass, co-doped core preform having a refractive index alpha profile between 1.9 and 2.2 measured at 850 nm; depositing a cladding comprising silica over the sintered glass, co-doped preform to form a multi-mode optical fiber preform; drawing the optical fiber preform into a multi-mode optical fiber. A fluorine doping parameter is adjusted taking into account the doping temperature, preferably at least 1250°C, the fluorine dopant partial pressure and the radial thickness of the soot preform.