摘要:
A cylindrical preform (11) is drawn in its longitudinal direction to be a plastic optical fiber (21) by a drawing process (27). The preform (11) is produced by polymerizing an inner clad material in a hollow portion of an outer clad pipe (23) to form an inner clad (15), and then polymerizing a core material in a hollow portion of the inner clad (15) to form a core (12). After the polymerization of the inner clad material, the outer clad pipe (23) is subject to a heating under reduced pressure (25) to reduce penetration of the inner clad material into the outer clad pipe (23), such that a concentration of the inner clad material and its polymer penetrated in said outer shell is no more than 1.6 wt. %. Accordingly, an unevenness viscosity of the melted preform (11) for the drawing is reduced and the obtained plastic optical fiber (21) has an uniform transmission property.
摘要:
Polymerizable composition, whose main component is MMA, is injected into a clad tube (12) of PVDF. Then the clad tube (12) is inserted into a polymerization reactor (33). Three heaters (35a to 35c) are arranged along the longitudinal direction of the polymerization reactor (33). The set temperature of the heater (35a) at the left is 56° C., that of the heater (35b) at the center is 58° C., and that of the heater (35c) at the right is 60° C. The polymerization reaction is performed with rotating drive rolls (34) at 500 rpm to 3000 rpm. As a result, an inner clad layer (40) with constant thickness, whose main component is PMMA, is formed. A core (41) is formed inside the inner clad layer (40) to obtain a preform (16). The preform (16) is drawn to be a POF (18) having a constant diameter.