Exploiting nonreciprocity in BOTDA systems

Area of Science:

• Optics and Photonics
• Nonlinear Optics
• Fiber Optic Sensing

Background:

• Brillouin optical time-domain analysis (BOTDA) is crucial for distributed fiber sensing.
• Existing BOTDA methods for retrieving Brillouin phase-shift spectrum (BPS) distribution can be complex, requiring phase modulation, filtering, and high-bandwidth detectors.

Purpose of the Study:

• To present a novel and simplified technique for distributed measurements in BOTDA.
• To retrieve the position-resolved Brillouin phase-shift spectrum (BPS) along an optical fiber.

Main Methods:

• Utilizing the nonlinear phase-shift induced by stimulated Brillouin scattering.
• Employing a Sagnac interferometer (SI) to leverage its sensitivity to nonreciprocal phase-shifts.
• Theoretical description, numerical simulations, and experimental validation.

Main Results:

• Demonstration of a simplified method for BPS distribution retrieval in optical fibers.
• Successful position-resolved BPS measurement without phase modulation, filtering, or high-bandwidth detectors.
• Validation of the technique through theoretical, numerical, and experimental approaches.

Conclusions:

• The proposed Sagnac interferometer-based technique offers a simplified approach to distributed BOTDA measurements.
• This method eliminates the need for complex components, making BPS retrieval more accessible.
• The findings pave the way for more efficient and straightforward fiber optic sensing applications.