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Fading suppression and noise reduction of a DAS system integrated multi-core fiber
Optics Express
|November 14, 2024
Summary
This study introduces a novel distributed acoustic sensing (DAS) system using multi-core fiber (MCF) to suppress coherent fading. The spatial rotated-vector-average (SRVA) method effectively reduces noise and improves signal quality in fiber optic sensing.
Area of Science:
- Optoelectronics
- Fiber Optics
- Sensing Technology
Background:
- Multi-core fiber (MCF) offers independent light transmission in multiple spatial channels, making it attractive for distributed fiber sensing.
- Coherent fading is a significant challenge in distributed acoustic sensing (DAS) systems, limiting performance and reliability.
- Space-division multiplexing (SDM) technology, enabled by MCF's parallel cores, provides a pathway to overcome sensing limitations.
Purpose of the Study:
- To develop and validate a distributed acoustic sensing (DAS) system integrated with multi-core fiber (MCF) to effectively suppress coherent fading.
- To introduce and theoretically analyze the spatial rotated-vector-average (SRVA) method for fading suppression in MCF-based DAS.
- To demonstrate the performance improvements of the SRVA method compared to conventional techniques.
Main Methods:
- Integration of a multi-core fiber (MCF) into a distributed acoustic sensing (DAS) system.
- Theoretical analysis of the spatial rotated-vector-average (SRVA) method for merging spatial signals to reduce fading.
- Experimental investigation using a 2.58-km MCF-based DAS system.
Main Results:
- The SRVA method effectively reduced the fading rate of Rayleigh backscattered signals by three orders of magnitude.
- Amplitude fluctuation range was decreased by 21.9 dB, and noise level was reduced by 9.5 dB compared to the spectrum extraction and remix method (SERM).
- The system demonstrated mitigation of false alarms in localization and achieved distortionless phase recovery, with excellent low-frequency signal recovery.
Conclusions:
- The proposed SRVA method integrated with MCF-based DAS effectively suppresses coherent fading, significantly enhancing sensing performance.
- This approach overcomes key limitations in DAS systems, enabling more reliable and accurate long-distance fiber sensing.
- The findings support the application of SDM-based MCF in advanced integrated sensing and communication systems.
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