Multiple solution-doping in optical fibre fabrication I – Aluminium doping

This work is part of a study of solution-doping in Modified Chemical Vapour Deposition, as used in fabrication of specialty silica optical fibres. The present paper concentrates on aluminium solution-doping and the effects of introducing additional heat-treatment stages into the process. The behaviours of the aluminium salt when heat-treated independently and after deposition in the silica soot have been studied by X-ray diffractometry, thermo-gravimetric analysis with mass spectrometry, electron microscopy and microanalysis. It has been shown that a procedure involving multiple cycles of solution-soaking and heat-treatment of the soot layer increases the level of aluminium doping obtainable. Efficiency of aluminium incorporation has been measured in the soaked soot, the sintered glass layer and in the final collapsed preform. An interpretive model of the multiple cycle soak/heat-treatment process is suggested.

[1]  Won-Taek Han,et al.  Effect of soaking temperature on concentrations of rare-earth ions in optical fiber core in solution doping process , 2001, SPIE OPTO.

[2]  S. Houde-Walter,et al.  Local structure of Er3+ in multicomponent glasses , 1998 .

[3]  E. M. Dianov,et al.  Doping of optical fiber preforms via porous silica layer infiltration with salt solutions , 2005 .

[4]  H. Shih,et al.  The preparation of alumina fibre by sol-gel processing , 1994, Journal of Materials Science.

[5]  K. Sandhage,et al.  Indirect Dissolution of Sapphire into Calcia‐Magnesia‐Alumina‐Silica Melts: Electron Microprobe Analysis of the Dissolution Process , 1990 .

[6]  Takashi Handa,et al.  Aluminum or phosphorus co‐doping effects on the fluorescence and structural properties of neodymium‐doped silica glass , 1986 .

[7]  David N. Payne,et al.  Solution-doping technique for fabrication of rare-earth-doped optical fibres , 1987 .

[8]  R. Wyatt,et al.  Optical and structural analysis of neodymium-doped silica-based optical fibre , 1989 .

[9]  F. Riley,et al.  Thermal formation of corundum from aluminium hydroxides prepared from various aluminium salts , 2000 .

[10]  D. Petzold,et al.  Thermoanalytische Untersuchungen zur Bildung kristalliner A12O3-Formen bei der thermischen Zersetzung von Aluminiumchloridhexahydrat , 1981 .

[11]  C. Bertran,et al.  Sol-Gel Synthesis of Transparent Alumina Gel and Pure Gamma Alumina by Urea Hydrolysis of Aluminum Nitrate , 2004 .

[12]  M. Sacks,et al.  Mullite Formation by Endothermic Reaction of α‐Alumina/Silica Microcomposite Particles , 1996 .

[13]  R. Roy,et al.  Rapid Crystallization of SiO2‐Al2O3 Glasses , 1973 .

[14]  S. Komarneni,et al.  Diphasic xerogels, a new class of materials: phases in the system al2o3-sio2 , 2006 .

[15]  K. Walker,et al.  Consolidation of Participate Layers in the Fabrication of Optical Fiber Preforms , 1980 .

[16]  T. Imanaka.  A Mass Spectrometric Study of Aluminum Chloride , 1967 .

[17]  G. Beall,et al.  Immiscibility and Crystallization in A12O3‐SiO2 Glasses , 1969 .

[18]  A. Chakraborty.  Formation of Silicon‐Aluminum Spinel , 1979 .

[19]  N. N. Greenwood,et al.  Chemistry of the elements , 1984 .

[20]  Geoffrey W. Barton,et al.  Nanoscale characterization of silica soots and aluminium solution doping in optical fibre fabrication , 2006 .

[21]  J. A. Pask,et al.  Dependence of Phase Composition on Nuclei Available in SiO2-A12O3 Mixtures , 1978 .

[22]  B. Ainslie.  A review of the fabrication and properties of erbium-doped fibers for optical amplifiers , 1991 .