Abstract:
The present invention provides a method of making rare earth (RE) doped optical fiber using BaO as co-dopant instead of Al or P commonly used for incorporation of the RE in silica glass by MCVD and solution doping technique. The method comprises deposition of particulate layer of GeO 2 doped SiO 2 with or without small P 2 O 5 for formation of the core and solution doping by soaking the porous soot layer into an aqueous solution of RE and Ba containing salt. This is followed by dehydration and sintering of the soaked deposit, collapsing at a high temperature to produce the preform and drawing of fibers of appropriate dimension. The use of Ba-oxide enables to eliminate unwanted core-clad interface defect which is common in case of Al doped fibers. The fibers also show good RE uniformity, relatively low optical loss in the 0.6-1.6 μm wavelength region and good optical properties suitable for their application in amplifiers, fiber lasers and sensor devices.
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:
According to one example of the invention an optical fiber comprises: (i) silica based, rare earth doped core having a first index of refraction n1; (ii) at least one silica based cladding surrounding the core and having a second index of refraction n2, such that n 1 > n 2 ; wherein at least one of the core or cladding is doped with Al 2 O 3 , such that the ratio of max wt% to min wt% of Al 2 O 3 concentration is less than 2:1
Abstract translation:根据本发明的一个示例,光纤包括:(i)具有第一折射率n1的二氧化硅基稀土掺杂的核; (ii)至少一个围绕所述芯并且具有第二折射率n2的基于二氧化硅的包层,使得n1> n2; 其中所述芯或包层中的至少一个掺杂有Al 2 O 3,使得Al 2 O 3浓度的最大重量%与最小重量%的比率小于2:1
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:
The invention relates to a method for preparing doped oxide material, in which method substantially all the reactants (B, D) forming the oxide material are brought to a vaporous reduced form in the gas phase and after this to react with each other in order to form oxide particles (P). According to the invention, said reactants (B, D) in vaporous and reduced form are mixed together to a gas flow (BD) of reactants, which gas flow (BD) is further condensated fast in such a manner that substantially all the component parts of the reactants (B, D) reach a supersaturated state substantially simultaneously by forming oxide particles (P) in such a manner that there is no time to reach chemical phase balances.
Abstract:
The present invention provides an improved process for making rare earth doped preforms and fibres by a combination of MCVD technique and solution doping method, said method comprising developing matched or depressed clad structure inside a silica glass substrate tube followed by deposition of unsintered particulate layer containing GeO>2 25 3 3 3