Patent ID: 6970650

Claim:
A one-fiber bidirectional optical transmission system, comprising: an optical fiber transmission line that transmits a first signal light and a second signal light, wherein the first signal light is transmitted in a first direction from one input-output terminal to other input-output terminal, and the second signal light is transmitted in a second direction that is opposite to the first direction; a first Raman pump source that generates a first Raman pump light, wherein a Raman gain band of the first Raman pump light includes a frequency of the first signal light but does not include a frequency of the second signal light; a first injection unit that injects the first Raman pump light into the optical fiber transmission line from the other input-output terminal; a second Raman pump source that generates a second Raman pump light, wherein a Raman gain band of the second Raman pump light includes a frequency of the second signal light but does not include a frequency of the first signal light; and a second injection unit that injects the second Raman pump light into the optical fiber transmission line from the one input-output terminal, wherein a frequency relationship satisfies a following inequality, | f s1 âˆ’f 0 |â‰ |f p2 âˆ’f 0 | and | f s2 âˆ’f 0 |â‰ |f p1 âˆ’f 0 |, where f 0 is a zero dispersion frequency of the optical fiber transmission line, f s1 and f s2 are the frequencies of the first signal light and the second signal light, respectively, and f p1 and f p2 are frequencies of the first Raman pump light and the second Raman pump light, respectively.