光学
边带
反射计
解调
光时域反射计
物理
频率调制
示波器
瑞利散射
调幅
动态范围
带宽(计算)
光纤
时域
光纤传感器
探测器
电信
保偏光纤
频道(广播)
计算机科学
量子力学
微波食品加热
计算机视觉
作者
Yuyao Wang,Hua Zheng,Huan Wu,Dongmei Huang,Changyuan Yu,Chao Lü
出处
期刊:Optics Express
[The Optical Society]
日期:2023-04-24
卷期号:31 (11): 17165-17165
被引量:3
摘要
Rayleigh scattering-based distributed optical fiber sensors with long sensing distance and large dynamic range are highly desired for application scenarios such as vehicle tracking, structure health monitoring, and geological survey. To enlarge the dynamic range, we propose a coherent optical time domain reflectometry (COTDR) based on double-sideband linear frequency modulation (LFM) pulse. By utilizing I/Q demodulation, both the positive and negative frequency band of the Rayleigh backscattering (RBS) signal can be properly demodulated. Consequently, the dynamic range is doubled without increasing the bandwidth of signal generator, photodetector (PD), and oscilloscope. In the experiment, the chirped pulse with 10 μs pulse width and 498 MHz frequency sweeping range is launched into the sensing fiber. Single-shot strain measurement is achieved over 5 km single-mode fiber with a spatial resolution of 2.5 m and a strain sensitivity of 7.5 pε/Hz. A vibration signal with 3.09 με peak-to-peak amplitude (corresponding to 461 MHz frequency shift) is successfully measured with the double-sideband spectrum, which cannot be properly recovered with the single-sideband spectrum.
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