Optical fiber base material ingot and method for producing the same

Abstract

There are disclosed a method for producing an optical fiber base material ingot comprising depositing a soot on a starting core member, and subjecting the soot to dehydration, vitrification by sintering, and then cylindrical grinding, wherein the cylindrical grinding is performed while a core portion central axis is brought into line with a rotation axis of cylindrical grinding machine, and an optical fiber base material ingot produced by the method. According to the present invention, there are provided an optical fiber base material ingot having excellent ingot roundness and excellent core portion eccentricity, and a production method capable of producing the optical fiber base material ingot in a short period of time.

What is claimed is:  
     
         1 . A method for producing an optical fiber base material ingot comprising depositing a soot on a starting core member, and subjecting the soot to dehydration, vitrification by sintering, and then cylindrical grinding, wherein the cylindrical grinding is performed while a core portion central axis is brought into line with a rotation axis of cylindrical grinding machine.  
     
     
         2 . The method for producing an optical fiber base material ingot according to    claim 1   , wherein the core portion central axis is brought into line with the rotation axis of cylindrical grinding machine by detecting a position of core portion.  
     
     
         3 . The method for producing an optical fiber base material ingot according to    claim 1   , wherein, in the cylindrical grinding, finishing grinding is performed after at least rough grinding is performed.  
     
     
         4 . The method for producing an optical fiber base material ingot according to    claim 2   , wherein, in the cylindrical grinding, finishing grinding is performed after at least rough grinding is performed.  
     
     
         5 . The method for producing an optical fiber base material ingot according to    claim 1   , wherein the cylindrical grinding is performed by multi-edge grinding.  
     
     
         6 . The method for producing an optical fiber base material ingot according to    claim 2   , wherein the cylindrical grinding is performed by multi-edge grinding.  
     
     
         7 . The method for producing an optical fiber base material ingot according to    claim 3   , wherein the cylindrical grinding is performed by multi-edge grinding.  
     
     
         8 . The method for producing an optical fiber base material ingot according to    claim 4   , wherein the cylindrical grinding is performed by multi-edge grinding.  
     
     
         9 . An optical fiber base material ingot, which is produced by the method for producing an optical fiber base material ingot according to    claim 1   .  
     
     
         10 . An optical fiber base material ingot, which is produced by the method for producing an optical fiber base material ingot according to    claim 2   .  
     
     
         11 . An optical fiber base material ingot, which is produced by the method for producing an optical fiber base material ingot according to    claim 3   .  
     
     
         12 . An optical fiber base material ingot, which is produced by the method for producing an optical fiber base material ingot according to    claim 4   .  
     
     
         13 . An optical fiber base material ingot, which is produced by the method for producing an optical fiber base material ingot according to    claim 5   .  
     
     
         14 . An optical fiber base material ingot, which is produced by the method for producing an optical fiber base material ingot according to    claim 6   .  
     
     
         15 . An optical fiber base material ingot, which is produced by the method for producing an optical fiber base material ingot according to    claim 7   .  
     
     
         16 . An optical fiber base material ingot, which is produced by the method for producing an optical fiber base material ingot according to    claim 8   .