Proposal of Brillouin optical correlation-domain reflectometry (BOCDR)

Area of Science:

• Optoelectronics
• Fiber optic sensing
• Photonics

Background:

• Conventional Brillouin optical time-domain reflectometry (BOTDR) faces limitations in spatial resolution (<1 m) and measurement speed (5-10 minutes).
• Accurate strain and temperature monitoring along optical fibers is crucial for structural health and performance assessment.

Purpose of the Study:

• To develop a novel sensing technique, Brillouin optical correlation-domain reflectometry (BOCDR), for high-resolution, rapid strain and temperature measurement.
• To overcome the inherent limitations of pulse-based reflectometry methods.

Main Methods:

• Utilizing continuous-wave lightwaves and controlling their interference to detect spontaneous Brillouin scattering.
• Implementing a single-ended measurement approach for distributed sensing.

Main Results:

• Achieved a spatial resolution of 40 cm, significantly surpassing the 1-m limit of conventional BOTDR.
• Demonstrated a high sampling rate of 50 Hz, enabling much faster measurements.
• Enabled random access to measurement positions along the fiber.

Conclusions:

• BOCDR offers a superior alternative to BOTDR for distributed strain and temperature sensing in optical fibers.
• The technique provides enhanced spatial resolution and measurement speed, opening new possibilities for real-time monitoring applications.