Simplified phase noise compensation architecture for distributed acoustic sensing enabled by receiver multiplexing.

Area of Science:

• Optoelectronics
• Fiber Optic Sensing
• Signal Processing

Background:

• Phase noise compensation (PNC) in distributed acoustic sensing (DAS) with coherent detection improves performance but adds complexity and cost.
• Existing PNC schemes require dedicated optical receivers for laser phase noise measurement, increasing system overhead.
• Relaxing light source coherence requirements is crucial for practical and cost-effective DAS implementations.

Purpose of the Study:

• To present a simplified PNC-DAS scheme that reduces hardware complexity.
• To enable simultaneous detection of Rayleigh scatterings and laser phase noise using a single coherent receiver.
• To demonstrate high-performance PNC without additional auxiliary interferometers.

Main Methods:

• Development of a novel PNC algorithm integrated into a single coherent receiver.
• Simultaneous measurement of backscattered Rayleigh signals and laser phase noise.
• Experimental validation of the simplified PNC-DAS system.

Main Results:

• Achieved a 49 km sensing range using a laser with a 100 kHz linewidth.
• Demonstrated a strain resolution of 78.2 pε/√Hz.
• Obtained a spatial resolution of 3.7 m without auxiliary interferometers.

Conclusions:

• The simplified PNC-DAS scheme effectively compensates for phase noise while reducing system complexity.
• This approach facilitates wider adoption of high-performance PNC in coherent detection DAS.
• The findings broaden the applicability of lasers for communication and sensing in DAS.