提出一种基于光梳状谱发生器(OFC)和注入锁定本地激光器的相干正交频分复用无源光网络(OFDM-PON)系统,通过理论计算及实验得出OFDM信号功率、本振光(LO)功率和注入比的最佳值。并对经过25 km单模光纤(SMF)传输后用半导体光放大器(SOA)、宽线宽从属激光器和窄线宽从属激光器提供外差接收本振光波的3种下行传输方案的误码率(BER)性能进行对比。实验结果表明激光器注入锁定不仅可以改善接收灵敏度,而且接收性能不受从属激光器固有线宽的影响,并能为上行传输提供相干光源。因此系统成本大大降低,为光相干检测技术在接入网和数据中心互联中的应用提供了可能性。

A coherent orthogonal frequency-division multiplexing passive optical network (OFDM-PON) system based on optical frequency comb (OFC) and injection locking local laser is proposed. Optimum OFDM signal power, optical local oscillator (LO) power and injection ratio are found by both theoretical calculation and experiments. The bit error rates (BER) performance of three kinds of downlink transmission are experimentally compared in which LO is provided by semiconductor optical amplifier (SOA), wide-linewidth slave laser and narrow-linewidth slave laser after 25 km single mode fiber (SMF) transmission. The results show that injection locking can improve the receiving sensitivity without affection by the inherent linewidth of the slave laser, and provide coherent light for uplink transmission. Therefore, the proposed system can reduce cost and provide the possibility for the application of the optical coherent detection technology in access networks and data-center interconnections.