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:
The application relates to an amplifying optical fiber having a central core and an optical cladding surrounding the central core, wherein the central core is based on a silica matrix comprising nanoparticles, which nanoparticles are composed of a matrix material comprising doping ions of at least one rare earth element. The matrix of the nanoparticle is chosen to favor rare earth solubility and dispersion and to favor the amplification process. In addition, the application relates to an optical amplifier and an optical laser comprising the present optical fiber. The invention relates to a method of preparing nanoparticles by adding compounds comprising the elements forming the nanoparticle to an aqueous solution with pH in the range of 6-10 under stirring. Further the invention relates to a method of manufacturing the present optical fiber comprising a heating step to strengthen the nanoparticles.
Abstract:
A tube (36) is connected to a different tube (27). A rod (22) is put in the different tube (27). Soot (28) is deposited on the outside of the different tube (27). A gas (55) is made to flow through the different tube (27). This structure (32) is then collapsed thereby creating an optical fiber preform.
Abstract:
Disclosed is a method of making an optical fiber preform having at least one annular region of depressed refractive index. A tube of silica doped with fluorine and/or boron is overclad with silica soot. A core rod is inserted into the overclad tube and the resultant assembly is heated while chlorine flows between the tube and the core rod to clean the adjacent surfaces. When the soot consolidates, the tube collapses onto and fuses to the rod. The resultant tubular structure is provided with cladding and drawn to form an optical fiber which exhibits low attenuation as a result of the low seed count at the interface between the inner core and the region that is doped with florine and/or boron.
Abstract:
A B₂O₃-doped tubular porous silica preform is heated, and a fluorine-containing gas, such as SiF₄ or CF₄, is flowed into its aperture. The temperature is sufficiently high to cause the fluorine-containing gas to decompose and form fluorine which dopes the preform. Also flowed into the aperture is a sufficient amount of BF₃ to prevent fluorine from reacting with the B₂O₃ in the porous preform and thereby inhibit formation of a B₂O₃-depleted region near the aperture surface. The doped porous preform is then consolidated to fuse the particles and form a dense glass tube containing both boron and fluorine as dopants with substantially uniform radial composition profiles (see fig.5). Optical fibres can be placed in the dense glass tube which is then collapsed to form a fibre optic coupler.
Abstract:
Incorporation of fluorine into a porous silica body, such as an unsintered body produced by a sol-gel method, by VAD or OVPO, reduces or eliminates bubble or pore formation upon re-heating of the glass formed by sintering of the porous material. Effective fluorine concentrations are between 0.01 and 5% by weight. The invention can be used advantageously in producing preforms and optical fiber.
Abstract:
The invention provides a novel method for the preparation of a synthetic quartz glass body substantially free from hydroxy groups as a class of undesirable impurities when the quartz glass body is used as a precursor of optical fibers. The method comprises subjecting a gaseous mixture composed of a silicon compound and a fluorine-containing hydrocarbon compound such as carbon tetrafluoride and trifluoro chloromethane to combustion or thermal decomposition in an oxidizing condition to form silicon dioxide which is deposited on the substrate to form a porous sintered body to be subsequently melted into a transparent quartz glass body. When the silicon compound and the fluorine-containing hydrocarbon compound contain no chlorine atoms, the resultant quartz glass body is also free from chlorine impurity undesirable in optical fibers. The above principle is applied to the direct preparation of a precursor rod of optical fibers by conducting the combustion or oxidative decomposition of the silicon compound in the space surrounded by the inner wall of a quartz glass tube outwardly heated at such an intensity that the silicon dioxide is deposited in transparent quartz glass layers.