Luo Linqing, Parmigiani Francesca, Yu Yifei, Li Bo, Soga Kenichi, Yan Jize
Opt Express. 2018 Feb 19;26(4):3870-3881. doi: 10.1364/OE.26.003870.
The sensitivity of a sensor to strain or the temperature variations due to distributed Brillouin scattering are partially related to the type of fibers used and the Brillouin scattering induced effective index. In this paper, a highly nonlinear fiber that can generate a higher Brillouin scattering signal is compared to a standard single mode fiber in a short-time-Fourier-transform Brillouin optical time domain reflectometer (STFT-BOTDR). The results show that much higher signal to noise ratios of the Brillouin scattering spectrum and smaller frequency uncertainties in the sensing measurement can be achieved in the highly nonlinear fiber for comparable launched powers. With a measurement speed of 4 Hz, the frequency uncertainty can be 0.43 MHz, corresponding to 10 με in strain or 0.43°C in temperature uncertainty for the highly nonlinear fiber. In contrast, for the standard single mode fiber case, the value would increase to about 1.02 MHz (25 με or 1.02°C), demonstrating the advantage of the highly nonlinear fiber for distributed strain/temperature sensing.
传感器对由于分布式布里渊散射引起的应变或温度变化的灵敏度部分与所使用的光纤类型以及布里渊散射诱导的有效折射率有关。在本文中，在短时傅里叶变换布里渊光时域反射仪（STFT-BOTDR）中，将能够产生更高布里渊散射信号的高非线性光纤与标准单模光纤进行了比较。结果表明，在可比的发射功率下，高非线性光纤中布里渊散射光谱的信噪比要高得多，并且传感测量中的频率不确定性更小。在测量速度为4 Hz时，高非线性光纤的频率不确定性可以为0.43 MHz，对应于应变中的10 με或温度不确定性中的0.43°C。相比之下，对于标准单模光纤的情况，该值将增加到约1.02 MHz（25 με或1.02°C），这证明了高非线性光纤在分布式应变/温度传感方面的优势。
