提出并设计了一种基于正交光相干接收的光载波上下边带信号分离技术,可用在布里渊散射分布式光纤传感系统中,实现对斯托克斯光和反斯托克斯光的无损分离。该技术利用正交光相干接收技术,保留了光场的相位信息,使光载波的上下边带在不同的输出端口处于相干叠加或相干抵消状态,从而实现上下边带的分离。结果表明,该技术可使光载波的上下边带分别从两个端口输出,且输出与输入信号功率线性相关,具有很好的线性度。分离之后的上边带光信号和下边带光信号之间的串扰小于-20 dB。与常用的光学滤波器方法相比,该技术无温度敏感器件,具有很好的稳定性和可靠性。

We propose a technique to separate the upper and the lower sidebands of an optical carrier based on orthogonal optical coherent receiving, which can be used in Brillouin scattering distributed fiber-optic sensing systems to separate Stokes and anti-Stokes scattering without loss. In the orthogonal optical coherent receiving technology, phase information of the optical field is preserved. So the upper and the lower sidebands can be arranged in coherent addition or cancellation states in different outputs, and the separation of the upper and the lower sidebands is realized. The results show that the technique can output the upper and lower sidebands from different ports, with a good linear relationship between input power and output power. The crosstalk between the separated upper and lower sidebands can be less than -20 dB. Compared with frequently employed optical filtering, this technique has no temperature sensitive component and shows good stability and robustness.