Chow C W, Yeh C H
Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan.
Opt Express. 2010 Dec 6;18(25):26046-51. doi: 10.1364/OE.18.026046.
As different high speed signal-remodulation wavelength division multiplexed--passive optical network (WDM-PON) solutions up to 10 Gb/s have been proposed, researchers are going to further increase the data rate of PON towards 40 Gb/s or higher. However, scaling up from 10 Gb/s/wavelength to 40 Gb/s/wavelength PON is very challenging. Although many studies have been performed on upgrading the exiting 10 Gb/s network to 40 Gb/s, the study of the 40 Gb/s signal-remodulation network is very little. In this work, we will first study the chromatic dispersion effect on the signal-remodulation PON. Then, we will propose and demonstrate a signal-remodulation PON using 40-Gb/s downstream differential-phase shift keying (DPSK) and 40-Gb/s upstream on-off keying (OOK) signals. By using the reduced modulation index (RMI) of the downstream DPSK signal, the tolerance to the residual chromatic dispersion of the whole system can be greatly enhanced. Due to the reduced impact of the accumulated chromatic dispersion, the quality of the upstream remodulated OOK signal can be significantly improved. Besides, by detecting the downstream demodulated DPSK signal at the destructive output port of the demodulator, good quality of the demodulated DPSK signal can still be achieved.
由于已经提出了高达10 Gb/s的不同高速信号重调制波分复用无源光网络（WDM-PON）解决方案，研究人员打算进一步将无源光网络的数据速率提高到40 Gb/s或更高。然而，从10 Gb/s/波长扩展到40 Gb/s/波长的无源光网络极具挑战性。尽管已经开展了许多将现有10 Gb/s网络升级到40 Gb/s的研究，但对40 Gb/s信号重调制网络的研究却非常少。在这项工作中，我们将首先研究色散对信号重调制无源光网络的影响。然后，我们将提出并演示一种使用40 Gb/s下行差分相移键控（DPSK）和40 Gb/s上行开关键控（OOK）信号的信号重调制无源光网络。通过使用下行DPSK信号的降低调制指数（RMI），可以大大提高整个系统对残余色散的容忍度。由于累积色散的影响降低，上行重调制OOK信号的质量可以得到显著改善。此外，通过在解调器的相消输出端口检测下行解调的DPSK信号，仍可实现高质量的解调DPSK信号。
