Monday, November 23, 2015



 Vapor Phase Deposition

  Flame Hydrolysis                                                                            Chemical Vapor Deposition


  Vapor Axial Deposition                                                                  Modified chemical  
  Outside vapour phase Oxidation                                                   Plasma-  activated chemical



       Optical fiber are made from oxide glasses and most popular is silica (SiO2) which has refractive index of 1.458 at 850 nm.
       To produce two similar materials with slightly different refraction indices for core and cladding, either fluorine or other oxides (dopants) are added to silica
 


 

Similar to outside vapor deposition
Starts with a seed which is a pure silica rod
The preform is grown in the axial direction by moving rod upward
Rod is also rotated to maintain cylindrical symmetery
As preform moves upward it is transformed into a solid transparent rod preform by zone melting (heating in a narrow localized zone)
Advantages
No central hole
                                                                        

Sunday, November 22, 2015

Vapor Phase Deposition method for optical fiber grade glass preparation

Vapor Phase deposition method for optical fiber grade glass preparation
This technique is used for preparing the extremely pure optical glasses.It is now used to produce silica based fiber with a very low attenuation(a fabrication process in which a material is stretched out into a thin shape),highest transparency with optimal optical properties.
Ingredients are volatile organic compounds SiCl4, GeCl4,SiF4,BCl4,O2,BBr3,PoCl3 and dopants (non silica ) are used to enhance the property of refractive index are TiO2,GeO2,P2O5,Al2O3,B2O3,F .



Vapor phase deposition
Flame Hydrolysis                                                                           Chemical Vapor Deposition
Vapor Axial Deposition    
Outside                           vapour phase Oxidation        
                                        
Modified chemical vapor phase

                                                         
Plasma- activate chemical