Patent ID: 7536876

Claim:
A method of forming a longitudinal solid body within an optical fiber having at least one longitudinal hole, comprising the steps of: placing a first end and a portion of the optical fiber in a heating chamber; keeping a second end of said optical fiber outside of the heating chamber; heating the heating chamber to at least a temperature at which a material to be introduced into said hole is molten; forcing the molten material into the longitudinal hole of the fiber from the first end; and thereupon longitudinally extracting the optical fiber, containing molten material, from the heated heating chamber at a controlled rate in order to solidify the molten material in the at least one longitudinal hole from one end of the fiber only, wherein the step of extracting the optical fiber from the heating chamber is performed while a pressing force is maintained, acting to urge the molten material into the hole of the fiber from the first end thereof.