Abstract: A method of manufacturing a preform, the method including positioning at least one glass tube in a glass outer cladding to form a preform precursor, the glass tube comprising a first open end and a second open end, forming a preform from the preform precursor, and thermally treating at least one of the preform precursor and the preform. The thermally treating including sealing the first open end and the second open end of the glass tube to form a closed tube and heating and/or cooling the glass tube to manipulate gas pressure within the closed glass tube.

Abstract: The present disclosure is directed to various embodiments of methods for making an optical fiber. The methods may include drawing an optical fiber from a hollow-core preform. The hollow-core preform may include an annular support structure with an inner surface defining an interior cavity. The interior cavity may include a tube in direct contact with the inner surface of the annular support structure. The tube may include a wall defining an internal opening, the internal opening having a sealed end. The drawing may include regulating a pressure of the internal cavity to a predetermined pressure.

Abstract: A system for element tracking in documents includes a memory device, a database, and a processor. The memory device is configured to store a mapping in a memory between a linked element within a document and a database object. The database is configured to store the database object. The processor is configured to in response to an update of the database object: a) cause storage in the database of an update event associated with the linked element; and b) provide an update indication that the update associated with the linked element has occurred.

Abstract: Preparation of halogen-doped silica is described. The preparation includes doping silica with high halogen concentration and sintering halogen-doped silica to a closed-pore state in a gas-phase environment that has a low partial pressure of impermeable gases. Impermeable gases are difficult to remove from halogen-doped fiber preforms and lead to defects in optical fibers drawn from the preforms. A low partial pressure of impermeable gases in the sintering environment leads to a low concentration of impermeable gases and a low density of gas-phase voids in densified halogen-doped silica. Preforms with fewer defects result.

Abstract: A method of forming an optical fiber, including: exposing a soot core preform to a dopant gas at a pressure of from 1.5 atm to 40 atm, the soot core preform comprising silica, the dopant gas comprising a first halogen doping precursor and a second halogen doping precursor, the first halogen doping precursor doping the soot core preform with a first halogen dopant and the second halogen precursor doping the soot core preform with a second halogen dopant; and sintering the soot core preform to form a halogen-doped closed-pore body, the halogen-doped closed-pore body having a combined concentration of the first halogen dopant and the second halogen dopant of at least 2.0 wt %.

Abstract: 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.

Abstract: A system for element tracking in documents includes a memory device, a database, and a processor. The memory device is configured to store a mapping in a memory between a linked element within a document and a database object. The database is configured to store the database object. The processor is configured to in response to an update of the database object: a) cause storage in the database of an update event associated with the linked element; and b) provide an update indication that the update associated with the linked element has occurred.

Abstract: A system for element tracking in documents includes a memory device, a database, and a processor. The memory device is configured to store a mapping in a memory between a linked element within a document and a database object. The database is configured to store the database object. The processor is configured to in response to an update of the database object: a) cause storage in the database of an update event associated with the linked element; and b) provide an update indication that the update associated with the linked element has occurred.

Abstract: Preparation of halogen-doped silica is described. The preparation includes doping silica with high halogen concentration and sintering halogen-doped silica to a closed-pore state. The sintering includes a high pressure sintering treatment and a low pressure sintering treatment. The high pressure sintering treatment is conducted in the presence of a high partial pressure of a gas-phase halogen doping precursor and densifies a silica soot body to a partially consolidated state. The low pressure sintering treatment is conducted in the presence of a low partial pressure of gas-phase halogen doping precursor and transforms a partially consolidated silica body to a closed-pore state. The product halogen-doped silica glass exhibits little foaming when heated to form fibers in a draw process or core canes in a redraw process.

Abstract: A method of forming an optical fiber, including: exposing a soot core preform to a dopant gas at a pressure of from 1.5 atm to 40 atm, the soot core preform comprising silica, the dopant gas comprising a first halogen doping precursor and a second halogen doping precursor, the first halogen doping precursor doping the soot core preform with a first halogen dopant and the second halogen precursor doping the soot core preform with a second halogen dopant; and sintering the soot core preform to form a halogen-doped closed-pore body, the halogen-doped closed-pore body having a combined concentration of the first halogen dopant and the second halogen dopant of at least 2.0 wt %.

Abstract: Preparation of halogen-doped silica is described. The preparation includes doping silica with high halogen concentration and sintering halogen-doped silica to a closed-pore state in a gas-phase environment that has a low partial pressure of impermeable gases. Impermeable gases are difficult to remove from halogen-doped fiber preforms and lead to defects in optical fibers drawn from the preforms. A low partial pressure of impermeable gases in the sintering environment leads to a low concentration of impermeable gases and a low density of gas-phase voids in densified halogen-doped silica. Preforms with fewer defects result.

Abstract: Preparation of halogen-doped silica is described. The preparation includes doping silica with high halogen concentration and sintering halogen-doped silica to a closed-pore state. The sintering includes a high pressure sintering treatment and a low pressure sintering treatment. The high pressure sintering treatment is conducted in the presence of a high partial pressure of a gas-phase halogen doping precursor and densifies a silica soot body to a partially consolidated state. The low pressure sintering treatment is conducted in the presence of a low partial pressure of gas-phase halogen doping precursor and transforms a partially consolidated silica body to a closed-pore state. The product halogen-doped silica glass exhibits little foaming when heated to form fibers in a draw process or core canes in a redraw process.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: One embodiment of the disclosure relates to a method of making an optical fiber comprising the steps of: (i) exposing a silica based preform with at least one porous glass region having soot density of ? to a gas mixture comprising SiCl4 having SiCl4 mole fraction ySiCl4 at a doping temperature Tdop such that parameter X is larger than 0.03 to form the chlorine treated preform, wherein X = 1 1 + [ ( ? ? s - ? ) ? 0.209748 ? ? T dop ? Exp ? [ - 5435.33 / T dop ] y SiCl ? ? 4 3 / 4 ] and ?s is the density of the fully densified soot layer; and (ii) exposing the chlorine treated preform to temperatures above 1400° C. to completely sinter the preform to produce sintered optical fiber preform with a chlorine doped region; and (iii) drawing an optical fiber from the sintered optical preform.

Abstract: A soot deposition burner assembly, having at least one burner including a burner face on a first surface of a burner support. The burner produces a flame which extends generally perpendicularly to the first surface. A burner shield includes a first wall extending generally perpendicularly from the first surface surrounding the burner face. The burner shield has a base end with a first surface area facing toward the first surface and a shield face with a second surface area facing away from the first surface. To reduce the buildup of soot material, the second surface area is smaller than the first surface area, and the wall thickness is less at the shield face than the base end. Additionally, air can be directed along an exterior surface of the first wall from the base end toward the shield face to further reduce soot buildup.

Abstract: One embodiment of the disclosure relates to a method of making an optical fiber comprising the steps of: (i) exposing a silica based preform with at least one porous glass region having soot density of ? to a gas mixture comprising SiCl4 having SiCl4 mole fraction ySiCl4 at a doping temperature Tdop such that parameter X is larger than 0.03 to form the chlorine treated preform, wherein X = 1 1 + [ ( ? ? s - ? ) ? 0.209748 ? ? T dop ? Exp ? [ - 5435.33 / T dop ] y SiCl ? ? 4 3 / 4 ] and ?s is the density of the fully densified soot layer; and (ii) exposing the chlorine treated preform to temperatures above 1400° C. to completely sinter the preform to produce sintered optical fiber preform with a chlorine doped region; and (iii) drawing an optical fiber from the sintered optical preform.

Abstract: One embodiment of the disclosure relates to a method of making an optical fiber comprising the steps of: (i) exposing a silica based preform with at least one porous glass region having soot density of ? to a gas mixture comprising SiCl4 having SiCl4 mole fraction ySiCl4 at a doping temperature Tdop such that parameter X is larger than 0.03 to form the chlorine treated preform, wherein X = 1 1 + [ ( ? ? s - ? ) ? 0.209748 ? T dop ? Exp ? [ - 5435.33 / T dop ] y SiCl ? ? 4 3 / 4 ] and ?s is the density of the fully densified soot layer; and (ii) exposing the chlorine treated preform to temperatures above 1400° C. to completely sinter the preform to produce sintered optical fiber preform with a chlorine doped region; and (iii) drawing an optical fiber from the sintered optical preform.

Abstract: A soot deposition burner assembly, having at least one burner including a burner face on a first surface of a burner support. The burner produces a flame which extends generally perpendicularly to the first surface. A burner shield includes a first wall extending generally perpendicularly from the first surface surrounding the burner face. The burner shield has a base end with a first surface area facing toward the first surface and a shield face with a second surface area facing away from the first surface. To reduce the buildup of soot material, the second surface area is smaller than the first surface area, and the wall thickness is less at the shield face than the base end. Additionally, air can be directed along an exterior surface of the first wall from the base end toward the shield face to further reduce soot buildup.