Optical fiber and method of making the same
AssigneeSumitomo Electric Industries, Ltd.
InventorsMasaaki Hirano, Masashi Onishi, Yoshio Yokoyama
Life of this patent
Estimating the term…
Abstract
An optical fiber is composed of silica glass and comprises a center core region doped with F element, a ring core region doped with GeO2, and an inner cladding region doped with F element; wherein a buffer layer composed of undoped SiO2 or SiO2 doped with one or both of P and Cl or a concentration gradient region in which GeO2 concentration radially decreases toward the boundary is provided between the center core region and the ring core region.
Claims19
An optical fiber, composed of silica glass, having a center core region doped with fluorine element and a ring core region doped with germanium dioxide;
- said optical fiber further comprising a buffer layer disposed between said center core region and said ring core region, said buffer layer being composed of undoped silicon dioxide or silicon dioxide doped with one or both of phosphorus and chlorine.
An optical fiber, composed of silica glass, having a center core region doped with fluorine element and a ring core region doped with germanium dioxide;
- wherein, letting a [μm] be the radius of said center core region, and CG(r) [wt %] be the concentration of germanium dioxide in said ring core region at a position separated from the center by a radius r [μm], the concentration gradient yG1 [wt %·μm2] of germanium dioxide in a boundary portion of said ring core region with respect to said center core region defined by:
- 9 y G1 = ∫ a a + 1 ( rC G ( r ) exp ( a - r ) ) ⅆ r ( 1 )
- is 100 wt %·μm2 or less.
An optical fiber, composed of silica glass, having a center core region doped with fluorine element and a ring core region doped with germanium dioxide;
- wherein, letting a [μm] be the radius of said center core region, and CF(r) [wt %] be the concentration of fluorine element in said center core region at a position separated from the center by a radius r [μm], the concentration gradient yF1 [wt %·μm2] of fluorine element in a boundary portion of said center core region with respect to said ring core region defined by:
- 10 y F1 = ∫ a - 1 a ( rC F ( r ) exp ( r - a ) ) ⅆ r ( 2 )
- is 18 wt %·μm2 or less.
An optical fiber, composed of silica glass, having a center core region, a ring core region doped with germanium dioxide, and an inner cladding region doped with fluorine element, all of which are arranged concentrically;
- said optical fiber further comprising a buffer layer disposed between said ring core region and said inner cladding region, said buffer layer being composed of undoped silicon dioxide or silicon dioxide doped with one or both of phosphorus and chlorine.
An optical fiber, composed of silica glass, having a center core region, a ring core region doped with germanium dioxide, and an inner cladding region doped with fluorine element;
- wherein, letting b [μm] be the radius of said ring core region, and CG(r) [wt %] be the concentration of germanium dioxide in said ring core region at a position separated from the center by a radius r [μm], the concentration gradient yG2 [wt %·μm2] of germanium dioxide in a boundary portion of said ring core region with respect to said inner cladding region defined by:
- 11 y G2 = ∫ b - 1 b ( rC G ( r ) exp ( r - b ) ) ⅆ r ( 3 )
- is 180 wt %·μm2 or less.
An optical fiber, composed of silica glass, having a center core region, a ring core region doped with germanium dioxide, and an inner cladding region doped with fluorine element, all of which are arranged concentrically;
- wherein, letting b [μm] be the radius of said ring core region, and CF(r) [wt %] be the concentration of fluorine element in said inner cladding region at a position separated from the center by a radius r [μm], the concentration gradient yF2 [wt %·μm2] of fluorine element in a boundary portion of said inner cladding region with respect to said ring core region defined by:
- 12 y F2 = ∫ b b + 1 ( rC F ( r ) exp ( b - r ) ) ⅆ r ( 4 )
- is 30 wt %·μm2 or less.
A method of making an optical fiber comprising the steps of:
- preparing a silica glass pipe having a layer doped with germanium dioxide at least on an inner periphery side thereof;
- depositing undoped silicon dioxide or silicon dioxide doped with one or both of phosphorus and chlorine onto the inside of said silica glass pipe, so as to produce a buffer layer;
- inserting a silica glass rod doped with fluorine element into the inside of said buffer layer, and then heating and unifying said silica glass rod and said buffer layer, so as to prepare an intermediate preform;
- and
- melt-spinning an optical fiber preform including said intermediate preform.
A method of making an optical fiber comprising the steps of:
- preparing a silica glass pipe having a layer doped with germanium dioxide at least on an inner periphery side thereof;
- heating said silica glass pipe, so as to evaporate germanium dioxide in an inner surface thereof and eliminate germanium dioxide in a surface layer;
- inserting a silica glass rod doped with fluorine element into the inside of said silica glass pipe, and then heating and unifying said silica glass rod and said silica glass pipe, so as to prepare an intermediate preform;
- and
- melt-spinning an optical fiber preform including said intermediate preform.
A method of making an optical fiber comprising the steps of:
- preparing a silica glass pipe having a layer doped with fluorine at least on an inner periphery side thereof;
- depositing undoped silicon dioxide or silicon dioxide doped with one or both of phosphorus and chlorine onto the inside of said silica glass pipe, so as to form a buffer layer;
- further forming at an inner peripheral portion thereof a glass layer doped with germanium dioxide, so as to produce an intermediate pipe;
- inserting a silica glass rod into the inside of said intermediate pipe, and then heating and unifying said silica glass rod and said intermediate pipe, so as to prepare an intermediate preform;
- and
- melt-spinning an optical-fiber preform including said intermediate preform.
A method of making an optical fiber comprising the steps of:
- concentrically forming, successively from the axial center side, a silica layer, a layer doped with germanium dioxide, and an undoped layer or a layer doped with one or both of phosphorus and chlorine, so as to prepare a silica glass rod;
- preparing a silica glass pipe having a layer doped with fluorine at least on an inner periphery side thereof;
- inserting said silica glass rod into said silica glass pipe, and then heating and unifying said silica glass rod and said silica glass pipe, so as to prepare an intermediate preform;
- and
- melt-spinning an optical fiber preform including said intermediate preform.
A method of making an optical fiber comprising the steps of:
- preparing a silica glass pipe having a layer doped with fluorine at least on an inner periphery side thereof;
- depositing undoped silicon dioxide or silicon dioxide doped with one or both of phosphorus and chlorine onto the inside of said silica glass pipe, so as to form a buffer layer;
- forming a silica glass rod having a silica layer at the axial center and a layer doped with germanium dioxide therearound;
- inserting said silica glass rod into the inside of said buffer layer, and then heating and unifying said silica glass rod and said buffer layer, so as to prepare an intermediate preform;
- and
- melt-spinning an optical fiber preform including said intermediate preform.
A method of making an optical fiber comprising the steps of:
- preparing a silica glass rod having a silica layer on the axial center side and a ring-shaped layer doped with germanium dioxide disposed on the outside thereof;
- opening said silica glass rod along the axis, so as to prepare a silica glass pipe;
- inserting a silica glass rod doped with fluorine element into the inside of said silica glass pipe, and then heating and unifying said silica glass rod and said silica glass pipe, so as to form an intermediate preform;
- and
- melt-spinning an optical fiber preform including said intermediate preform.
Dependencies are inferred from the claim text.