Urricelqui Javier, Sagues Mikel, Loayssa Alayn
Departamento de Ingeniería Eléctrica y Electrónica, Universidad Pública de Navarra Campus Arrosadia, 31006 Pamplona, Spain.
Opt Express. 2013 Jul 15;21(14):17186-94. doi: 10.1364/OE.21.017186.
We demonstrate a Brillouin optical time domain analysis sensor based on a phase-modulated probe wave and RF demodulation that provides measurements tolerant to frequency-dependent variations of the pump pulse power induced by non-local effects. The tolerance to non-local effects is based on the special characteristics of the detection process, which provides an RF phase-shift signal that is largely independent of the Brillouin gain magnitude. Proof-of-concept experiments performed over a 20-km-long fiber demonstrate that the measured RF phase-shift spectrum remains unaltered for large frequency-dependent deformations of the pump pulse power. Therefore, it allows the use of a higher optical power of the probe wave, which leads to an enhancement of the detected signal to noise ratio. This can be used to extend the sensing distance, to improve the accuracy of the Brillouin frequency shift measurements, and to reduce the measurement time.
我们展示了一种基于相位调制探测波和射频解调的布里渊光时域分析传感器，该传感器能够提供对由非局部效应引起的泵浦脉冲功率频率相关变化具有耐受性的测量结果。对非局部效应的耐受性基于检测过程的特殊特性，该特性提供了一个很大程度上与布里渊增益幅度无关的射频相移信号。在一根20公里长的光纤上进行的概念验证实验表明，对于泵浦脉冲功率的大幅频率相关变形，测得的射频相移光谱保持不变。因此，它允许使用更高功率的探测波光，这会提高检测到的信噪比。这可用于延长传感距离、提高布里渊频移测量的精度并减少测量时间。
