Discriminating Rayleigh backscattering induced false crosstalk in inline interferometric FBG sensor arrays.

Area of Science:

• Optoelectronics
• Fiber optic sensing
• Multiplexing technologies

Background:

• Crosstalk in interferometric fiber Bragg grating (FBG) arrays limits performance.
• Existing crosstalk issues include time-division (multiple reflections) and wavelength-division (insufficient isolation) in Fabry-Perot (F-P) structures.
• These limitations restrict the number of multiplexing devices and system applications.

Purpose of the Study:

• To investigate a newly discovered crosstalk phenomenon termed "false crosstalk" in hybrid multiplexing arrays.
• To develop a theoretical model analyzing the causes and influencing factors of false crosstalk.
• To provide insights for optimizing array design and increasing multiplexing capacity.

Main Methods:

• Constructed a theoretical model to analyze false crosstalk.
• Investigated the influence of Rayleigh backscattering (RB) noise and sensor position on false crosstalk.
• Validated theoretical findings with experimental results.

Main Results:

• The theoretical model demonstrated the impact of RB noise and sensor position on false crosstalk.
• False crosstalk is induced by parasitic interference within the leading fiber.
• False crosstalk performance degrades with changes in sensor position and leading fiber length.

Conclusions:

• False crosstalk is a significant performance-limiting factor in hybrid multiplexing arrays.
• Understanding the role of leading fiber interference is crucial for mitigating false crosstalk.
• This research offers quantitative data to optimize sensor placement and enhance large-scale multiplexing capabilities.