Photonics Research Center, School of Science, Harbin Engineering University, Harbin, China.
Opt Lett. 2011 Sep 1;36(17):3380-2. doi: 10.1364/OL.36.003380.
The higher-order interference noise that is caused by multireflection at the fiber sensor's end surface in low-coherence fiber sensor array is proposed. The generation of the higher-order interference noise and its quantity and amplitude are theoretically analyzed. The second-order interference noises are experimentally demonstrated. The results show that the second-order noises arise in any sensor array composed of more than two sensors and the number of the second-order peaks is proportional to the third power of the sensor's number. The ratio of the amplitude of the second-order noise to that of the signal peak is proportional to the reflectivity of the sensor's end surface. In a sensor array, when the reflectivity is more than 10(-5), the amplitude of the second-order noise is higher than other noises and it becomes a main factor that determines the signal-to-noise ratio of the sensor arrays. Therefore, reducing the higher-order interference noise can improve the multiplexing capacity of the sensor array.
提出了在低相干光纤传感器阵列中光纤传感器端面多次反射引起的高阶干涉噪声。从理论上分析了高阶干涉噪声的产生及其数量和幅度。实验验证了二阶干涉噪声。结果表明，二阶噪声出现在由两个以上传感器组成的任何传感器阵列中，二阶峰的数量与传感器数量的立方成正比。二阶噪声的幅度与信号峰值的幅度之比与传感器端面的反射率成正比。在传感器阵列中，当反射率大于 10(-5)时，二阶噪声的幅度高于其他噪声，成为决定传感器阵列信噪比的主要因素。因此，降低高阶干涉噪声可以提高传感器阵列的复用能力。
