报道了高速率单信道非归零差分相移键控(NRZ-DPSK)调制信号的长距离光纤环路传输。光纤环路总长414 km,由4个放大段组成。每个放大段由标准单模光纤(SSMF)和色散补偿光纤(DCF)构成,采用掺铒光纤放大器/分布式拉曼放大器(EDFA/DRA)混合放大。测量了42.8 Gb/s差分相移键控信号在环路传输1,2,3圈(414 km,828 km和1242 km)后的光谱和眼图。在接收段使用单端检测的条件下,给出了DPSK信号在背对背情况,414 km和1242 km传输后的误码率(BER)随接收机功率变化的曲线。DPSK信号在1242 km传输后最低误码率可达6.3×10-4。在使用增强型前向纠错(FEC)技术后,能实现无误码传输。

The high-speed single-channel transmission of nonreturn-to-zero differential phase-shift keying (NRZ-DPSK) signal is demonstrated using fiber loop. The 414 km fiber loop is divided into four spans,which consist of standard single-mode fiber (SSMF) and dispersion compensation fiber (DCF),and erbium-doped fiber amplifier/distributed Raman amplifier (EDFA/PRA) are used for hybrid amplification. The optical spectrum and eye diagrams of 42.8 Gb/s DPSK signal are obtained after 414 km,828 km and 1242 km transmission. The curves of bit error rate (BER) of the DPSK signal are given both in back-to-back configuration and after transmission using single-ended detection. The BER is 6.3×10-4 after 1242 km transmission,and the error-free transmission can be realized using enhanced forward error correction (FEC).