Optical fiber drawing system for non-contact control of polarization mode dispersion of optical fiber

Abstract

Disclosed is a system for drawing an optical fiber for controlling polarization mode dispersion. A furnace is provided for uniformly heating an optical fiber preform in the drawing system mounted to an optical fiber draw tower. The furnace comprises: (a) a main body; (b) a sub-body placed coaxially with the main body and having a diameter smaller than that of the main body; and (c) an upper gas feeding section over the main body, wherein the upper gas feeding section includes a first hollow rotary body having at least one slit in the inner surface thereof along the longitudinal direction of an optical fiber and at least one opening extended in the direction of the center, whereby a gas artificially/periodically creates non-contact polarization to the optical fiber by the first hollow rotary body. Effective non-contact control can be carried out about polarization mode dispersion of the optical fiber.

What is claimed is:  
     
         1 . A furnace for uniformly heating an optical fiber preform in an optical fiber draw tower, said furnace comprising: 
 a main body;    a sub-body placed coaxially with said main body and having a diameter smaller than said main body; and,    an upper gas feeding section disposed over said main body, wherein said upper gas feeding section includes a first hollow rotary body having at least one slit in the inner surface thereof along the longitudinal direction of an optical fiber and at least one opening extended in the direction of the center, whereby a gas creates non-contact polarization to the optical fiber through said first hollow rotary body.    
     
     
         2 . The furnace according to  claim 1 , further comprising a middle gas feeding section between said main body and said sub-body, wherein said middle gas feeding section includes a second hollow rotary body having at least one slit in the longitudinal direction of the optical fiber.  
     
     
         3 . The furnace according to  claim 1 , further comprising a lower gas feeding section under said sub-body, wherein said lower gas feeding section includes a third hollow rotary body having at least one slit along the longitudinal direction of the optical fiber.  
     
     
         4 . The furnace according to  claim 1 , where in said slit is linearly extended about the longitudinal direction of the optical fiber.  
     
     
         5 . The furnace according to  claim 2 , wherein said slit is linearly extended about the longitudinal direction of the optical fiber.  
     
     
         6 . The furnace according to  claim 3 , wherein said slit is linearly extended about the longitudinal direction of the optical fiber.  
     
     
         7 . The furnace according to  claim 1 , wherein said slit is inclined at an angle about the longitudinal direction of the optical fiber.  
     
     
         8 . The furnace according to  claim 2 , wherein said slit is inclined at an angle about the longitudinal direction of the optical fiber.  
     
     
         9 . The furnace according to  claim 3 , wherein said slit is inclined at an angle about the longitudinal direction of the optical fiber.  
     
     
         10 . The furnace according to  claim 1 , wherein said slit is spirally provided about the longitudinal direction of the optical fiber.  
     
     
         11 . The furnace according to  claim 2 , wherein said slit is spirally provided about the longitudinal direction of the optical fiber.  
     
     
         12 . The furnace according to  claim 3 , wherein said slit is spirally provided about the longitudinal direction of the optical fiber.  
     
     
         13 . An apparatus for cooling an optical fiber drawn from an optical fiber preform in drawing systems mounted to an optical fiber draw tower, said apparatus comprising: 
 a main body extended in length; and    an upper gas feeding section over said main body, wherein said upper gas feeding section includes a first hollow rotary body having at least one slit in the inner surface thereof along the longitudinal direction of the optical fiber and at least one opening extended in the direction of the center, whereby a gas creates non-contact polarization to the optical fiber by said first hollow rotary body.    
     
     
         14 . The apparatus according to  claim 13 , wherein said slit is linearly extended about the longitudinal direction of the optical fiber.  
     
     
         15 . The apparatus according to  claim 13 , wherein said slit is inclined at an angle about the longitudinal direction of the optical fiber.  
     
     
         16 . The apparatus according to  claim 13 , wherein said slit is spirally provided about the longitudinal direction of the optical fiber.