Laser & Optoelectronics Progress, Volume. 60, Issue 23, 2306006(2023)
Distributed Optical Fiber Micro-Seismic Signal Modulation System Based on Linear Frequency Modulation
Based on the traditional distributed optical fiber sensing technology that uses back Rayleigh scattering, a linear sweep pulse modulation method for micro-seismic detection is proposed. The rectangular pulse in the modulation system is first transformed into a linear sweep pulse, and long-distance and high-spatial-resolution sensing is realized by compressing the pulse and matching filtering. Through simulation and experimental verifications, a narrow line-width laser with a line width of approximately 10 kHz is selected as the light source. Electro-optical and acousto-optical modulations determine the frequency scanning range and time as 5.6‒5.8 GHz and 2 μs, respectively. Linear sweep signal modulation obtains a sensing distance of 10 km, and the intensity range of the received back Rayleigh scattering signal is -60~-50 dBm.
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Shaojie Cui, Jiehu Kang, Bin Wu. Distributed Optical Fiber Micro-Seismic Signal Modulation System Based on Linear Frequency Modulation[J]. Laser & Optoelectronics Progress, 2023, 60(23): 2306006
Category: Fiber Optics and Optical Communications
Received: Nov. 1, 2022
Accepted: Jan. 6, 2023
Published Online: Dec. 8, 2023
The Author Email: Wu Bin (wubin@tju.edu.cn)