| 摘要 |
PROBLEM TO BE SOLVED: To form a mode conversion part in a desired tapered shape in a plastic optical fiber by an easy method. SOLUTION: A tapered area 2a is held so that tapered areas 2c and holding members 40 which are larger in heat capacity than their peripheries are covered in contact. Then a hot blast is blown to one side of the optical fiber 2 about the tapered areas 2c held by the holding members 40. The optical fiber 2 is heated on one side about the tapered areas and held at the original temperature on the other side. The optical fiber 2 has a temperature gradient generated from one tapered area 2c to the other. Therefore, when the heated optical fiber 2 is fixed by the holding members 40 and drawn, tapered parts 2c' which increase in diameter from one tapered area 2c to the other according to the temperature of the respective parts of the tapered areas 2c can easily be formed. |
