基于SOA的交叉相位调制生成UWB信号的研究

Generation of UWB Signal Based on the Cross-Phase Modulation in SOA

超宽带信号(UWB)的光学生成技术是光载超宽带通信系统(UWB-over-fiber)的关键技术,半导体光放大器(SOA)的非线性特征在全光信号处理中有着广泛的应用。提出基于SOA的交叉相位调制(XPM)效应的UWB的光学生成方法。该方法首先利用SOA的XPM实现高功率的高斯泵浦光和低功率的直流探测光的XPM,然后利用光学滤波器对探测光进行鉴频,实现相位调制到强度调制的转换,从而获得单周期UWB信号。提出了采用光带通滤波器和波分复用器对探测光进行鉴频的两种方法,获得中心频率分别为5.15GHz和5.05GHz,相对带宽分别为150%和149%的UWB信号,符合FCC标准。

The photonic generation of uhrawideband （UWB） signal is a key technology of UWB-over-fiber system. The nonlinear feature in semiconductor optical amplifier （SOA） is widely applied in the area of all-optical signal processing. A method is proposed to generate UWB pulse using the cross-phase modulation in SOA. In this method, the low-power continuous wave probe light is phase modulated by the high-power pump light which is realized by XPM in SOA, then the optical filter is used as a frequency discriminator to realized the conversion from PM to AM, so as to obtain a monocycle UWB. Two methods are proposed, one is realized by utilizing an optical bandpass filter as the frequency discriminator; the other by utilizing a DWDM as the frequency discriminator. As a result, we obtain the UWB pulses which have 5.15 GHz and 5.05 GHz of center frequency, and 150% and 149% of fraction bandwidth, respectively. It meets the standard of FCC.