中文摘要：

将25km普通单模光纤（SMF）和高非线性光子晶体光纤（PCF）共同作为增益介质组成分布式混合光纤Raman放大器（H—FRA），并考虑前向、后向和双向3种泵浦方式和2种不同参数的PCF在光纤链路的不同位置，研究了其增益和噪声特性。结果表明，当PCF位于增益光纤链路的尾端时，H—FRA具有较好的噪声性能；H—FRA的开关增益不仅与PCF在光纤链路中的位置有关，还与其插入损耗和泵浦方式有关；对位于链路尾端的后向和双向泵浦H—FRA，增益和噪声性能均最佳。

英文摘要：

A distributed hybrid-fiber Raman amplifier（H-FRA） with 25 km single-mode fiber （SMF） and a section of photonic crystal fiber（POF） is proposed and demonstrated. Its onoff gain and noise performance are experimentally investigated in detail. In our experiment,the H-FRAs with three pump schemes and two POF types with different parameters and length,which are placed at different location of the fiber link,were considered. The experimental results indicate that the optical signal-to-noise ratios （OSNRs） of the H-FRAs are always better when the POFs are located at the span end. Whereas,the on-off gains are not only dependent on the position of the POF in the span,but also related to the POF loss and pump configuration. The on-off gain and noise performance are both better when the POF is inserted at the span end for backward- and bi-directional-pumped schemes.