基于半导体光放大器的四波混频效应对正交频分复用光信号进行全光波长变换

All-Optical Wavelength Conversion Based on Four-Wave Mixing in Semiconductor Optical Amplifier for OFDM Optical Signal

实验研究了基于半导体光放大器(SOA)的四波混频(FWM)效应的单抽运光正交频分复用(OFDM)信号的波长变换系统。信号光源和抽运光源分别由两个不同输出波长的可调分布反馈式激光器(DFB-LD)产生。信号光源经2.5Gb/sOFDM的电信号直接调制后再和抽运光源耦合,经光放大器后在SOA实现波长变换。实验结果显示,耦合信号经SOA四波混频效应后,产生新波长的信号光将携带OFDM信号,且转换效率与信号光和抽运光的功率、波长以及两者的偏振夹角有关。同时也测量了转换的OFDM信号的功率-误码曲线和接收星座图。

We have theoretically and experimentally investigated all optical wavelength conversion based on four-wave mixing （FWM） in a semiconductor optical amplifier （SOA）. Pump and signal lightwaves are generated from two different distributed feedback laser diodes （DFB-LDs）. 2 Gbit/s orthogonal frequency division multiplexing （OFDM） is used to modulate directly on the signal CW lightwave. The modulated signal lightwave and pump are coupled and then amplified before they are injected into the SOA for wavelength conversion based on four wave mixing effect. Experimental result shows that the newly converted wavelength signals copy the original OFDM signals and its conversion efficiency of the converted signals are proportional to the amplitudes of the input signal and the pumps under the condition of SOA non-saturation. The polarization angle between the pump and signal lightwave affects the optical power of the converted OFDM signal. The bit error rate （BER） curves and receive constellation are also measured.