偏振复用光OFDM信号全光波长变换的理论与实验研究

All-optical wavelength conversion (AOWC) has been regarded as one of the key techniques key for optical networks, which can enhance the wavelength routing capacity and network re-configurability. Four-wave mixing (FWM) is considered to be the most promising scheme, because it is fully transparent to the signal bit rate and modulation format. Orthogonal frequency division multiplexing (OFDM) technique has the advantage of high spectral efficiency, and in optical communication system, OFDM signal has strong dispersion and polarization mode dispersion (PMD) resistance. Moreover, orthogonal frequency division multiplexing combined with optical polarization multiplexing has higher capacity. This project includes the following parts: The influence of FWM effect on OFDM signal in the AOWC will be investigated, and the noise can be reduced by some methods; Several conditions to affect the conversion efficiency are also discussed, and the optimal performance of the system can be obtained; Based on the theoretical analysis, AOWC for coherent optical OFDM will be numerically demonstrated,and the optimal system performance can be obtainde. Theses researches are significant in both theory and practice for the AOWC of polarization optical OFDM signal.

全光波长变换技术（AOWC）作为全光网络的关键技术之一，可以解决网络波长拥塞和竞争问题。而基于四波混频效应进行全光波长变换的方式是现在仅有的可对信号透明转换的途径。将正交频分复用（OFDM）信号应用到光通信领域中形成光正交频分复用（OOFDM）系统，可以抵抗光纤色散和偏振模色散，而将OFDM技术与偏振复用技术相结合，具有更高的频谱利用率。 因此，本课题将对基于四波混频效应的光OFDM 信号的全光波长变换进行探索与研究。具体包括探索研究：光正交频分复用信号全光波长变换的透明性研究，分析偏振串扰对偏振复用光OFDM信号全光波长变换的影响，研究符合实际情况的理论模型，探索设计和验证无偏振串扰的偏振复用光OFDM信号的全光波长变换系统。本课题对基于四波混频效应的偏振复用光OFDM 信号的全光波长变换系统的实现具有理论与现实指导意义。

高速率和大容量传输已成为信息传输的目标，正交频分复用技术与偏振复用技术相结合可以增加单波通信速率。未来光网络需要在传输节点引入全光波长变换技术，解决网络波长拥塞和竞争问题，提高光节点的处理能力。因此，本项目对基于四波混频效应的光正交频分复用信号的全光波长变换进行探索与研究。具体包括：提出了一个成本有效、偏振不敏感且宽可调谐的基于四波混频效应的正交频分复用信号的波长转换系统，分析得到在信噪比相同的情况下，该方案的波长可调范围大于平行泵浦方案和垂直泵浦方案。通过建立基于四波混频效应的偏振复用正交频分复用信号全光波长变换的数学模型，揭示了偏振串扰对偏振复用光正交频分复用信号全光波长变换的影响，设计了无偏振串扰的偏振复用光正交频分复用信号全光波长变换系统。此外，我们还发展了基于四波混频效应全光波长变换原理在光载无线通信系统中的应用研究，产生了高倍频和多频率的毫米波信号。