Method and apparatus for removing polymeric coatings from optical fiber

Abstract

In accordance with the invention, the polymeric coating is removed from a coated optical fiber by disposing the fiber within a low pressure environment and applying sufficient heat to volatilize at least a portion of the polymeric coating. The result is that the coating material bursts from the fiber, yielding a clean glass surface virtually free of surface flaws. In a preferred embodiment the heat is provided by a resistive filament heater within a vacuum chamber.

What is claimed is:  
     
         1 . A method for removing the coating from a polymeric coated optical fiber comprising the steps of: 
 disposing the coated optical fiber within an evacuable chamber;    evacuating the chamber to a pressure of less than about 2 Torr; and    applying to the fiber sufficient heat to volatilize at least a portion of the polymeric coating thereby causing the coating to burst away from the fiber.    
     
     
         2 . The method of  claim 1  wherein the chamber is evacuated to a pressure of less than about 200 mTorr.  
     
     
         3 . The method of  claim 1  wherein heat is applied to the fiber by at least one resistive filament heater.  
     
     
         4 . The method of  claim 3  wherein the resistive filament heater is heated to a glow temperature in excess of 800° C.  
     
     
         5 . The method of  claim 3  wherein the resistive filament heater is heated to a temperature in excess of 1500° C.  
     
     
         6 . The method of  claim 1  wherein sufficient heat is applied to the fiber to cause the coating to burst away from the fiber in less than about 3 seconds.  
     
     
         7 . Apparatus for removing the coating from a polymeric coated optical fiber comprising: 
 an evacuable chamber; and    one or more heating elements for heating the coated fiber along the length of coating to be removed.    
     
     
         8 . The apparatus of  claim 7  wherein the one or more heating elements each comprise a resistive filament heater.  
     
     
         9 . The apparatus of  claim 7  wherein the one or more heating elements comprise a series of resistive filament heaters, the series extending along the length of coating to be removed.  
     
     
         10 . The apparatus of  claim 7  wherein the evacuable chamber comprises a two-part chamber for sealingly engaging together about the coated optical fiber.  
     
     
         11 . The apparatus of  claim 7  wherein each heating element comprises an open loop resistive filament.  
     
     
         12 . The apparatus of  claim 8  wherein each heating element comprises a resistive filament heater of refractory metal.