| 摘要 |
PURPOSE:To enable signal light to be sufficiently amplified to the power required for long distance transmission by a device of compact size and low cost by a method wherein a normal input exciting means or inverse input exciting means inputting exciting means in the transmitting direction are arranged respectively on the input side or the output side of an amplifying optical fiber. CONSTITUTION:A pumping light beam is introduced along the transmitting direction of signal light from a normal input pumping means 4 provided on the input side of an amplifying optical fiber 2. Bisides, another pumping light beam is introduced along the reverse direction to the transmitting direction of the signal light from a reverse input exciting means 12 provided on the output side of the amplifying optical fiber 2. At this time, the same pumping effect is given on the amplifying optical fiber 2 regardless of the forward or reverse input direction of the pumping light beams to the amplifying optical fiber 2. Accordingly, the amplifying optical fiber 2 is excited by respective pumping light beams so that the signal light may be amplified dually by the induced emission effect corresponding to the respective pumping light. Thus, the title photoamplifier of compact size and low cort is capable of sufficiently amplifying the signal light to the power required for a long distance transmission. |
