초록 ▼

A method of forming an alkali metal oxide-doped optical fiber by diffusing an alkali metal into a surface of a glass article is disclosed. The silica glass article may be in the form of a tube or a rod, or a collection of tubes or rods. The silica glass article containing the alkali metal, and impur

A method of forming an alkali metal oxide-doped optical fiber by diffusing an alkali metal into a surface of a glass article is disclosed. The silica glass article may be in the form of a tube or a rod, or a collection of tubes or rods. The silica glass article containing the alkali metal, and impurities that may have been unintentionally diffused into the glass article, is etched to a depth sufficient to remove the impurities. The silica glass article may be further processed to form a complete optical fiber preform. The preform, when drawn into an optical fiber, exhibits a low attenuation.

대표청구항 ▼

We claim: 1. An optical fiber wherein the core is comprised of SiO2 and an alkali metal oxide of the form X2O where X is selected from the group consisting of K, Na, Li, Cs and Rb and 0.035≦X2O≦6 mole percent, wherein said core is further comprised of less than about 100 ppm chlorine an

We claim: 1. An optical fiber wherein the core is comprised of SiO2 and an alkali metal oxide of the form X2O where X is selected from the group consisting of K, Na, Li, Cs and Rb and 0.035≦X2O≦6 mole percent, wherein said core is further comprised of less than about 100 ppm chlorine and less than about 100 ppb -OH, and wherein an optical attenuation of the optical fiber at a wavelength of 1550 nm is less than 0.18 dB/km. 2. The optical fiber of claim 1 wherein said core is comprised of less than about 50 ppm Cl. 3. The optical fiber of claim 1 wherein said core of said optical fiber is comprised of less than about 20 ppb -OH. 4. An optical fiber, comprising: SiO2 and an alkali metal oxide in the form of X2O where X is selected from a group consisting of K, Na, Li, Cs and Rb, and GeO2; and wherein an optical attenuation at 1550 nm is less than 0.18 dB/km. 5. The optical fiber according to claim 4 wherein the alkali metal oxide and the GeO2 are present in a core of the optical fiber. 6. The optical fiber according to claim 5 wherein a chlorine content in the core is less than 500 ppm. 7. The optical fiber according to claim 6 wherein a chlorine content in the core is less than 100 ppm. 8. The optical fiber according to claim 7 wherein a chlorine content in the core is less than 50 ppm. 9. The optical fiber according to claim 6 wherein a water content in the core is less than 100 ppb. 10. The optical fiber according to claim 9 wherein the water content in the core is less than 20 ppb. 11. An optical fiber, comprising: a core comprising SiO2 and an alkali metal oxide in the form of X2O and GeO2, where X is selected from a group consisting of K, Na, Li, Cs and Rb; and wherein an optical attenuation at 1550 nm of the optical fiber is less than about 0.18 dB/km.