Lalam Nageswara, Bhatta Hari, Sun Xiaoguang, Lu Ping, Ohodnicki Paul, Buric Michael P, Wright Ruishu
Opt Express. 2023 Oct 23;31(22):36590-36602. doi: 10.1364/OE.498141.
In this paper, we demonstrate a multi-parameter fiber sensing system based on stimulated Brillouin scattering in a double-Brillouin peak specialty fiber with enhanced Brillouin gain response. The amplitude level of the second Brillouin gain peak, which originated from the higher-order acoustic modes, has been improved with an approximately similar amplitude level to the first Brillouin gain peak from the fundamental acoustic mode. Compared to other multi-Brillouin peak fibers presented in the literature, the proposed fiber significantly reduces the measured Brillouin frequency shift error, thus improving strain and temperature accuracies. By utilizing the sensitivity values of the strain and temperature associated with each Brillouin gain spectrum (BGS) peak, a successful discriminative measurement of strain and temperature is performed with an accuracy of ±13 μɛ, and ±0.5 °C, respectively. The proposed double-Brillouin peak fiber appears to be a possible alternative to other multi-BGS peak fibers, for instance, large effective area fiber and dispersion compensating fibers, which are inherently accompanied by large measurement errors due to the weak Brillouin gain values originating from the higher-order acoustic modes. The demonstrated results show different strain and temperature coefficients of 47 kHz/µɛ, 1.15 MHz/°C for peak 1 and 51 kHz/µɛ, 1.37 MHz/°C for peak 2. Moreover, the enhanced BGS peak gains having nearly the same amplitude levels enable the discriminative measurement of strain and temperature. Such fibers in Brillouin interrogation eliminate the need for complex monitoring setups and reduce measurement errors. We recommend that for long-distance natural gas pipeline monitoring, where discriminative strain and temperature measurement is crucial, the proposed double-Brillouin peak fiber can be highly beneficial.
在本文中，我们展示了一种基于受激布里渊散射的多参数光纤传感系统，该系统采用了具有增强布里渊增益响应的双布里渊峰特种光纤。源自高阶声学模式的第二个布里渊增益峰的幅度水平得到了提高，其幅度水平与源自基模声学模式的第一个布里渊增益峰大致相似。与文献中提出的其他多布里渊峰光纤相比，该光纤显著降低了测量的布里渊频移误差，从而提高了应变和温度测量的精度。通过利用与每个布里渊增益谱（BGS）峰相关的应变和温度灵敏度值，分别以±13 μɛ和±0.5 °C的精度成功实现了应变和温度的判别测量。所提出的双布里渊峰光纤似乎是其他多BGS峰光纤（例如大有效面积光纤和色散补偿光纤）的一种可能替代方案，由于源自高阶声学模式的布里渊增益值较弱，这些光纤固有地伴随着较大的测量误差。实验结果表明，峰1的应变和温度系数分别为47 kHz/µɛ、1.15 MHz/°C，峰2的应变和温度系数分别为51 kHz/µɛ、1.37 MHz/°C。此外，增强后的BGS峰增益具有几乎相同的幅度水平，这使得能够对应变和温度进行判别测量。这种用于布里渊询问的光纤无需复杂的监测设置，并减少了测量误差。我们建议，对于需要进行判别性应变和温度测量的长距离天然气管道监测而言，所提出的双布里渊峰光纤可能会非常有用。
