Y-shaped optical branching coupler, an optical signal amplification method using the manufacturing method and the Y-shaped optical branching coupler

摘要

PURPOSE:To provide a Y type optical branching and coupling device which has small characteristic variation with ambient temperature and is small in loss. CONSTITUTION:A 2nd plastic fiber 11 is arranged almost in parallel to a 1st plastic fiber 10. The tip part of the 2nd plastic fiber 11 is finished in a tapered shape and adhered to the outer peripheral part of the 1st plastic fiber 10 by ultrasonic-wave excitation. The Y type optical branching and coupling device, therefore, consists of only the plastic fibers. Consequently, the Y type optical branching and coupling device is prevented from varying in characteristics with the temperature. Further, no transition part is present thereon, so the loss of the Y type optical branching and coupling device is reduced.