公开(公告)号：EP1167307B1

公开(公告)日：2002-12-18

申请号：EP01300127.6

申请日：2001-01-08

Applicant: LUCENT TECHNOLOGIES INC.

Inventor： Mazzarese, David J. ,  Oulundsen, George E. ,  Sledziewski Jr., Joseph T.

IPC: C03B37/012 ,  C03B37/018 ,  G02B6/18

CPC classification number: C03B37/01228 ,  C03B37/01861 ,  C03B37/01884 ,  C03B2201/31 ,  C03B2203/26 ,  Y02P40/57

公开(公告)号：EP1167307A1

公开(公告)日：2002-01-02

申请号：EP01300127.6

申请日：2001-01-08

Applicant: LUCENT TECHNOLOGIES INC.

Inventor： Mazzarese, David J. ,  Oulundsen, George E. ,  Sledziewski Jr., Joseph T.

IPC: C03B37/012 ,  C03B37/018 ,  G02B6/18

CPC classification number: C03B37/01228 ,  C03B37/01861 ,  C03B37/01884 ,  C03B2201/31 ,  C03B2203/26 ,  Y02P40/57

Abstract: The refractive index profile of a multimode optical preform, fabricated by MCVD for example, is modified in the longitudinal direction by removing selected amounts of core material from the wall of a central hole through the preform prior to collapse. The amount of core material to be removed is determined by measuring the refractive index profiles of optical fibers drawn from a number of precursor preforms at various locations along the length of the drawn fibers, averaging their profiles, and then comparing those averages with a desired profile. The refractive index profile is indirectly measured by bandwidth measurements, which are related to the alpha value a selected parameter (e.g., bandwidth) at various locations along the length of a fiber drawn from a previously fabricated preform. This parameter is then compared with desired values of that parameter at the various locations, and the differences are used to calculate the amount of core material that needs to be removed. Selective core material removal is accomplished by moving a torch along the length of the preform and flowing an etchant gas, such as a mixture of oxygen and SF 6 , through the central hole in the preform. Selective etching is accomplished by varying the flow rate and/or the concentration of the etchant gas and/or the torch speed as a function of the location of the torch along the length of the preform.

Abstract translation: 多模光纤预型件的折射率分布，通过MCVD制造对于实施例，在纵向方向上从中心孔的壁，通过塌缩之前预型件中除去芯材的选定量修改。 要除去芯部材料的量确定的由具有所需形状测量从多个在沿拉伸的纤维的长度的不同位置的前体的预成型件的拉伸光学纤维的折射率分布，平均为他们的简档，然后比较这些平均值开采 ， 折射率分布被间接带宽的测量，这是有关的阿尔法值在沿着从此前制造的预制件拉制光纤的长度的不同位置的选择的参数（例如，带宽）进行测定。 然后该参数相比具有的参数所需的值确实在各种位置，差异被用于计算并需要被去除的芯材料的量。 选择性芯材料去除是通过沿预制件的长度移动的焊炬和蚀刻剂气体，经过测试氧气和SF6的混合物的流动，通过在预型件的中心孔来实现的。 选择性蚀刻通过改变流速和/或蚀刻剂气体和/或焊炬速度沿预制件的长度的焊炬的位置的函数的浓度来完成。