Generating mechanism of maintaining force for optical fiber installed in ferrule hole

This paper describes a new theory of the maintaining force to keep the optical fiber in the ferrule hole, based on the theoretical analysis assuming the dimensional change among the ferrule, optical fiber, and epoxy adhesive layer, since the maintaining force is caused by the difference of linear expansion coefficients among those elements when temperature is changed. The major maintaining force for the optical fiber installed in the ferrule hole is caused by the radial compressive force applied to the cured epoxy adhesive layer, which caused by dimensional shrinking of the clearance between the optical fiber and the ferrule hole, due to a large amount of shrinkage in the ferrule and a small amount of shrinkage in the optical fiber when the temperature changes.