| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical transmission apparatus and an optical transmission method realizing single core two-way optical transmission with an extendable transmission range and a large capacity by using a single core optical fiber. <P>SOLUTION: A downlink signal optical receiver 115 receives a downlink signal light sent from a downlink signal optical transmitter 111 via an uplink downlink signal multiplexing/demultiplexing optical multiplexer/demultiplexer 112, an optical fiber transmission line 113, and an uplink downlink signal multiplexing/demultiplexing optical multiplexer/demultiplexer 114, and an uplink signal optical receiver 117 receives also an uplink signal from an uplink signal optical transmitter 116 via the path above in the opposite direction. An output signal from the downlink signal optical transmitter 111 creeps into the uplink signal optical receiver 117 through the uplink downlink signal multiplexing/demultiplexing optical multiplexer/demultiplexer 112, however, a wavelength difference between a downlink wavelength λ<SB>1</SB>(frequency f<SB>1</SB>) and an uplink wavelength λ<SB>2</SB>(frequency f<SB>2</SB>) is large, so that a beat noise component due to the interference of two waves exists outside the band of the uplink signal optical receiver 117, and the output signal gives no effect of coherent crosstalk, and power crosstalk is no problem because of large isolation. <P>COPYRIGHT: (C)2004,JPO |
