High-resolution and large-strain distributed dynamic sensor based on Brillouin and Rayleigh scattering.

Area of Science:

• * Optical Fiber Sensing
• * Photonics and Sensing Technology
• * Materials Science

Background:

• * Traditional optical time-domain reflectometry (OTDR) methods face limitations in measurement range and resolution.
• * Brillouin optical time domain analysis (BOTDA) offers a wide measurement range but lower resolution.
• * Frequency-scanning phase-sensitive optical time-domain reflectometry (Φ-OTDR) provides high resolution but a limited dynamic range.

Purpose of the Study:

• * To develop a hybrid optical fiber sensor merging BOTDA and Φ-OTDR for enhanced performance.
• * To overcome the inherent trade-offs between dynamic range and resolution in existing fiber optic sensing techniques.
• * To achieve simultaneous wide-dynamic-range and high-resolution strain and pressure measurements.

Main Methods:

• * Integration of BOTDA and Φ-OTDR using an adaptive signal corrector (ASC).
• * The ASC suppresses Φ-OTDR accumulated errors by referencing BOTDA data.
• * Utilized ordinary single-mode fiber for experimental validation.

Main Results:

• * Demonstrated a maximum strain variation of 302.9 µɛ with a resolution of 5.5 nɛ.
• * Achieved high-resolution dynamic pressure monitoring from 20 MPa to 0.29 MPa with 0.14-kPa resolution.
• * Successfully merged Brillouin and Rayleigh scattering sensor data, leveraging the advantages of both.

Conclusions:

• * The proposed hybrid sensor effectively combines wide dynamic range and high resolution.
• * This novel approach overcomes previous measurement limitations in optical fiber sensing.
• * Represents a significant advancement in achieving simultaneous high-resolution and wide-range sensing capabilities.