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