So for this system, in order to realize long distance transmission, the optical fiber dispersion coefficient must be small.

显然，对这种系统，要实现长距离传输，必须采用较低色散系数光纤。

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While optical fiber Raman laser (RFL) can be a good pump of FRA. The coupling coefficient between FRL and the transmission fiber is very small, so the pump and the amplifier can be compatible easily.

而光纤拉曼激光器(RFL)又作为FRA的泵浦源，它与光纤的耦合损耗小，可以实现泵浦与放大的良好兼容。

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