公开(公告)号：US06851281B2

公开(公告)日：2005-02-08

申请号：US10106868

申请日：2002-03-27

Applicant: Ranjan Sen ,  Mrinmay Pal ,  Mukul Chandra Paul ,  Shyamal Kumar Bhadra ,  Somesh Chatterjee ,  Kamal Dasgupta

Inventor： Ranjan Sen ,  Mrinmay Pal ,  Mukul Chandra Paul ,  Shyamal Kumar Bhadra ,  Somesh Chatterjee ,  Kamal Dasgupta

IPC: C03B37/018 ,  C03B37/075

CPC classification number: C03B37/01807 ,  C03B37/01838 ,  C03B37/01853 ,  C03B2201/12 ,  C03B2201/28 ,  C03B2201/31 ,  C03B2201/36

Abstract: The present invention provides a method of fabricating rare earth doped preforms and optical fibers by a combination of modified chemical vapor deposition (MCVD) process and solution doping technique said MCVD process is used to develop matched or depressed clad structure inside a silica glass substrate tube followed by deposition of porous silica soot layer containing GeO2, P2O5 or such refractive index modifiers by the backward deposition method for formation of the core and presintering the deposited particulate layer by backward pass with flow of GeCl4 and/or corresponding dopant halides, soaking the porous soot layer into an alcoholic/aqueous solution of RE-salts containing codopants such as AlCl3 in definite proportion, drying, oxidation, dehydration and sintering of the RE containing porous deposit and by collapsing at a high temperature to produce the preform followed by drawing the fibers by known technique to produce fibers with suitable core-clad dimensions and geometry.

Abstract translation: 本发明提供了一种通过改进的化学气相沉积（MCVD）工艺和溶液掺杂技术的组合制造稀土掺杂的预成型件和光纤的方法，所述MCVD工艺用于在石英玻璃衬底管内开发匹配或凹陷的包层结构，随后 通过用于形成芯的反向沉积方法沉积含有GeO 2，P 2 O 5或这种折射率改性剂的多孔二氧化硅烟灰层，并通过GeCl 4和/或相应的掺杂剂卤化物的流动反向通过沉积的颗粒层，浸泡多孔烟灰 将含有RE的多种沉积物的含RE的盐类，如AlCl 3的含水醇溶液/干燥，氧化，脱水和烧结，并在高温下收缩，制成预成型体，然后用纤维拉伸 已知的技术来生产具有合适的芯包层尺寸和几何形状的纤维。

公开(公告)号：US06889528B2

公开(公告)日：2005-05-10

申请号：US09982946

申请日：2001-10-22

Applicant: Ranjan Sen ,  Minati Chatterjee ,  Milan Kanti Naskar ,  Mrinmay Pal ,  Mukul Chandra Paul ,  Shyamal Kumar Bhadra ,  Kamal Dasgupta ,  Dibyendu Ganguli ,  Tarun Bandyopadhyay ,  Aharon Gedanken

Inventor： Ranjan Sen ,  Minati Chatterjee ,  Milan Kanti Naskar ,  Mrinmay Pal ,  Mukul Chandra Paul ,  Shyamal Kumar Bhadra ,  Kamal Dasgupta ,  Dibyendu Ganguli ,  Tarun Bandyopadhyay ,  Aharon Gedanken

IPC: C03B37/016 ,  C03B37/018 ,  G02B6/02 ,  G02B6/00

CPC classification number: B82Y30/00 ,  B82Y20/00 ,  C03B37/016 ,  C03B37/018 ,  C03B2201/12 ,  C03B2201/28 ,  C03B2201/31 ,  C03B2201/34 ,  C03B2201/36 ,  G02B6/02

Abstract: The present invention discloses a process for making rare earth (RE) doped optical fiber by using RE oxide coated silica nanoparticles as the precursor material, more particularly the method of the present invention involves preparation of stable dispersions (sol) of RE oxide coated silica nanoparticles at ambient temperature and applying a thin coating on the inner surface of silica glass tube following dip coating technique or any other conventional methods, of the said silica sol containing suitable dopants selected from Ge, Al, P, etc., the coated tubes were further processed into optical preforms by following MCVD technique and fiberized in desired configuration, the novelty lies in eliminating the step of the formation of porous soot layer at high temperature by CVD process inside a fused silica glass tube for formation of the core and also in the elemination of the incorporation of the rare earth ions into the porous soot layer following the solution doping technique or other conventional methods, the direct addition of RE oxides in the sol eliminates the formation of microcrystalites and clusters of rare earth ions and prevents change in composition including variation of RE concentration in the core which results in increase in the reproducibility and reliability of the process to a great extent, further the addition of Ge(OET)4 at ambient temperature in the silica sol reduces the quantity of GeCl4 which is required at high temperature to achieve the desired Numerical Aperture.

Abstract translation: 本发明公开了一种通过使用RE氧化物涂覆的二氧化硅纳米颗粒作为前体材料制备稀土（RE）掺杂光纤的方法，更具体地说，本发明的方法包括制备RE氧化物涂覆的二氧化硅纳米粒子的稳定分散体（sol） 在环境温度下，在浸渍涂布技术或任何其它常规方法之后，在石英玻璃管的内表面上施加薄涂层，所述硅溶胶含有选自Ge，Al，P等的合适的掺杂剂，所述涂覆的管进一步 通过遵循MCVD技术将其加工成光学预型件并在所需结构中纤维化，其新颖之处在于消除了在用于形成芯的熔融石英玻璃管内的CVD工艺在高温下形成多孔烟灰层的步骤，以及在电镀 在溶液掺杂技术或其它共混物之后将稀土离子掺入多孔烟灰层中 常规方法中，在溶胶中直接添加RE氧化物消除了微晶体和稀土离子簇的形成，并且防止了组分中包括核心中的RE浓度的变化的变化，这导致过程的再现性和可靠性增加到 在很大程度上，进一步在硅溶胶中在环境温度下添加Ge（OET）4 降低了在高温下所需的GeCl 4的量，以达到所需的数值 光圈。

公开(公告)号：US06751990B2

公开(公告)日：2004-06-22

申请号：US09800291

申请日：2001-03-06

Applicant: Tarun Bandyopadhyay ,  Ranjan Sen ,  Shyamal Kumar Bhadra ,  Kamal Dasgupta ,  Mukul Chandra Paul

Inventor： Tarun Bandyopadhyay ,  Ranjan Sen ,  Shyamal Kumar Bhadra ,  Kamal Dasgupta ,  Mukul Chandra Paul

IPC: C03B37018

CPC classification number: C03B37/01838 ,  C03B2201/12 ,  C03B2201/28 ,  C03B2201/31 ,  C03B2201/36 ,  Y02P40/57

Abstract: The present invention provides an improved process for making rare earth doped preforms and fibers 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 GeO2 and P2O5 for formation of the core and solution doping by soaking the porous soot layer into an alcoholic/aqueous solution of RE-salts containing co-dopants like AlCl3/Al(NO3)3 in definite proportion, controlling the porosity of the soot, dipping period, strength of the solution and the proportion of the codopants to achieve the desired RE ion concentration in the core and minimize the core clad boundary defects and followed by drying, oxidation, dehydration and sintering of the RE containing porous deposit and collapsing at a high temperature to produce the preform and overcladding with silica tubes of suitable dimensions and fiber drawing to produce fibers.

Abstract translation: 本发明提供了一种通过MCVD技术和溶液掺杂方法的组合制备稀土掺杂预成型件和纤维的改进方法，所述方法包括在石英玻璃基板管内形成匹配或凹陷的包层结构，随后沉积含有GeO 2的未烧结颗粒层 和P2O5，用于通过将多孔烟灰层以一定比例浸入含有Al-Al 3+（NO 3）3的共掺杂剂的RE盐的醇/水溶液中形成核心和溶液掺杂，控制烟灰的孔隙率，浸渍 时间，溶液的强度和共混物的比例以实现芯中期望的RE离子浓度，并使芯包覆边界缺陷最小化，随后使含RE的多孔沉积物进行干燥，氧化，脱水和烧结并在高处塌陷 温度以产生预制件并用适当尺寸的硅胶管和纤维拉伸制成外包层 纤维。