High-sensitivity optical fiber temperature-depth sensing array.

Area of Science:

• Oceanography
• Environmental Science
• Sensor Technology

Background:

• Accurate measurement of seawater temperature and depth is crucial for understanding ocean phenomena.
• Fiber optic sensors offer advantages like low cost, electromagnetic immunity, and easy integration for marine environmental detection.

Purpose of the Study:

• To propose a novel, highly sensitive temperature-depth sensor based on fiber Bragg gratings (FBGs).
• To develop a multi-point sensing array using FBGs for simultaneous temperature and depth measurements in aquatic environments.

Main Methods:

• Utilized a dual-FBG structure enhanced by etching, polymer packaging, and mechanical design for high sensitivity.
• Implemented wavelength division multiplexing to create a sensing array capable of multiple point measurements.
• Conducted lake experiments to validate the performance of the temperature-depth sensing array.

Main Results:

• Achieved high temperature sensitivity exceeding 145.16 pm/°C with a resolution better than 0.007 °C.
• Obtained high pressure sensitivity of 48.418 nm/MPa, yielding a depth resolution of approximately 2 mm.
• Demonstrated the capability of the FBG array for simultaneous, multi-point temperature and depth measurements in aquatic environments.

Conclusions:

• The proposed FBG-based temperature-depth sensor and array offer high performance for marine environmental monitoring.
• The sensing array exhibits broad application potential in shallow water layers, lakes, wetlands, and similar environments.
• This technology provides a robust solution for simultaneous, multi-point aquatic environmental sensing.