title: Higher-order interference of low-coherence optical fiber sensors.
abstract: 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.
authors: Photonics Research Center, School of Science, Harbin Engineering University, Harbin, China. yangjun141@263.net
authors: Jun
authors: J
authors: Yang
authors: Yonggui
authors: Y
authors: Yuan
authors: Bing
authors: B
authors: Wu
authors: Ai
authors: A
authors: Zhou
authors: Libo
authors: L
authors: Yuan