Abstract:
An optical fiber, comprising: (i) a rate earth doped silica based elongated core with a first refractive index (n 1 ) with an aspect ratio of 1:5 to 1; (ii) a silica based moat abutting and at least substantially surrounding the core, the moat having a refractive index n 2 , wherein n 2 1 ; (iii) a silica based inner cladding surrounding the moat, the inner cladding having a third refractive index (n 3 ), wherein n 1 >n 3 , and n 3 >n 2 , (iv) a silica based outer cladding surrounding said inner cladding, the outer cladding having a fourth refractive index (n 4 ), such that n 4 3 ; the optical fiber exhibits single polarization at the operating wavelenght band.
Abstract translation:一种光纤,包括:(i)具有1:5至1的纵横比的第一折射率(n <1> 1)的速率掺杂掺杂硅石的细长芯; (ii)邻接并且至少基本上围绕所述芯的基于二氧化硅的护城河,所述护城河具有折射率n 2 N 2,其中n 2 ; (iii)围绕所述护城河的基于二氧化硅的内包层,所述内包层具有第三折射率(n 3/3),其中n 1 <3> n 3 < (iv)围绕所述内包层的基于二氧化硅的外包层,所述外包层具有第四折射率(n 3) 4 SUB>),使得n 4 N 3 N 3; 光纤在工作波长带显示出单极化。
Abstract:
Disclosed is an optical fiber having a core of SiO 2 doped with fluorine and an alkali metal oxide dopant. The alkali metal oxide is selected from the group consisting of K, Na, Li, Cs and Rb and is provided in amount of at least 20 ppm wt. %. The fiber has an inner cladding surrounding the core, which also includes fluorine. A relative refractive index of the inner cladding (Δ 2 %), measured relative to pure silica, is preferably between -0.39 % and -0.7 %. The fiber preferably exhibits attenuation at 1550 nm of less than or equal to 0.178 dB/km.
Abstract:
Disclosed is an alkali-doped optical fiber preform and method for making the same. A silica glass member, such as a rod or the like is heated in a furnace chamber at a temperature of less than 75 C below the softening point of the glass rod in an environment containing an alkali metal vapor to form an alkali metal oxide doped glass rod. This method provides a peak concentration in the outer half portion of the silica glass member. The alkali metal oxide doped glass member may be overclad with additional glass to form an optical fiber preform ready for drawing into an optical fiber. Alternatively, the alkali metal oxide doped glass member may be inserted into a porous, glass soot optical fiber preform or inserted into a tube comprising solid glass.
Abstract:
Disclosed are a method for dehydration used in the optical fiber preform manufacturing process, and method and apparatus for manufacturing an optical fiber using the dehydration method. In the dehydration method, when the dehydrating gas is supplied into a tube during the optical fiber preform manufacturing process, dehydration reaction gas included in the dehydration gas is activated using a light source which emits light having a predetermined frequency capable of activating the dehydration reaction gas included in the dehydrating gas into atoms or ions. Then, the method uses the activated dehydration reaction gas generated as a result of the above process to eliminate moisture or hydroxyl group causing optical losses during the optical fiber preform manufacturing process.
Abstract:
A method of manufacturing an optical waveguide perform includes exposing a soot preform to an atmosphere including a chlorine-containing compound and thereby doping the soot preform with chlorine, wherein the absolute pressure of the atmosphere is greater than about 1.013 x 10 2 kPa. An apparatus for manufacturing an optical waveguide preform using a soot preform includes a furnace defining a chamber adapted to contain the soot preform and including a heating device operable to heat the chamber. A fluid control system is operable to provide an atmosphere including a chlorine-containing compound in the chamber at an absolute pressure of greater than about 1.013 x 10 2 kPa.
Abstract:
A silica soot preform (12) is inserted into a furnace (30). The preform is then treated with heat and carbon monoxide gas (32) so as to reduce impurities that could effect the final product.
Abstract:
An improved deposition machine is disclosed having a specially configured array of axially and azimuthally stacked burners, for depositing silica glass particles on an integral tube mandrel. The deposition machine includes a fire-polishing unit for fire-polishing the mandrel in-situ, immediately before the deposition process is performed, without having to cool, store and transfer the mandrel from one machine location to another. After the silica glass particles have been deposited on the mandrel, the preform is sintered. The integral tube mandrel preferably is configured to have a closed lower end, which enables the mandrel to be pressurized during both the fire-polishing step and the sintering step. This minimizes the risk of the mandrel losing its shape and it eliminates the possibility of heat rising through the tube mandrel by a chimney effect during the sintering step.