光子晶体光纤中交叉相位调制光谱展宽特性研究

实验研究了超高速时分复用信号与探测光同向传输,在色散平坦高非线性光子晶体光纤中的交叉相位调制光谱展宽特性,从光谱学的角度分析了信号光波长漂移,泵浦光与信号光总功率及功率比,二者偏振态失配对交叉相位调制光谱展宽效应的影响,探讨了实现偏振不敏感交叉相位调制效应的可行性。研究发现,在36 nm波长范围,总功率大于23 dBm,泵浦光与信号光功率比合理,二者偏振态匹配时交叉相位调制效果最好,交叉相位调制的偏振相关性为11 dB,指出利用色散平坦高非线性光子晶体光纤中的残余双折射,调节泵浦光与光纤双折射主轴成45°,可以实现偏振不敏感交叉相位调制效应,随后的理论模拟和实验结果相一致。研究结果为实现基于交叉相位调制原理工作的超快全光信号处理器件作了充分准备。

Study on spectral broadened characterization of cross phase modulation in photonic crystal fiber

Spectrum broadening induced by cross phase modulation (XPM) was investigated by exploiting the optical time-division multiplexing (OTDM) data signal and continue wave probe light co-propagation in dispersion flattened high nonlinear photonic crystal fiber (PCF). The effects of wavelength drift of probe lights, polarization mismatch, total power and power ration of pump and probe light on the spectrum broadening were analyzed. The results show that good XPM effects can be obtained in 36 nm wavelength range when the total power is higher than 23 dB, power ration of pump and probe light is appropriate and with identical polarization. Furthermore, polarization independent XPM effect can be achieved by using the remainder birefringence of the PCF with the pump state of polarization (SOP) aligned at 45 degrees to the PCF principal axes. The obtained results in this paper would be helpful for research on ultrahigh-speed all optical signal processing devices exploiting the XPM in PCF for future photonics network.