Patent ID: 6530243
Filing Date: 2003-03-11
Classification: C03B,C03C,Y02P

Abstract:
A method of drawing an optical fiber, comprising:drawing an optical fiber at a drawing speed of at least 50 m/min; coating said optical fiber with a UV-curing resin to yield a coated optical fiber having an outside diameter between about 300 to 600 &mgr;m; curing said UV-curing resin using at least one UV-curing furnace; and drawing said coated optical fiber downstream to a capstan configured to pull said coated optical fiber and then to a take up bobbin, and cooling said coated optical fiber to prevent deformation of said resin by ensuring that a pass line length zp between the most downstream outlet of said at least one UV-curing furnace to the most upstream entrance part of said capstan satisfies the following expression (1): zp&GreaterEqual;-Ï &it;â€ƒ&it;Cp_&CenterDot;d24&CenterDot;d22-d12A&CenterDot;Vf&CenterDot;ln&af;[(Tg-10)-ToTs-To]whereTg is the glass transition temperature of the coating resin [Â° C.]; TS is the fiber temperature [=TF (0)] at z=0 [Â° C.]; TO is the room temperature [Â° C]; {overscore (&rgr;Cp)} is the average heat capacity of glass and resin [J/(cm3Â·Â° C.)]; d1 is the radius before coating [cm]; d2 is the radius after coating [cm]; A is a given constant within the range of 1.5Ã—10âˆ’6 to 4.5Ã—10âˆ’6 [J/(secÂ·Â° C.]; and Vf is the drawing speed [cm/sec], and wherein said UV-curable resin has a glass transition temperature between about 80Â° C.-105Â° C.