Ultra-Weak Fiber Bragg Grating Sensing Network Coated with Sensitive Material for Multi-Parameter Measurements

Area of Science:

• Optoelectronics and Photonics
• Fiber Optic Sensing Technology
• Materials Science for Sensors

Background:

• Traditional fiber Bragg gratings (FBGs) are widely used for sensing but have limitations in multiplexing capacity.
• Developing high-density, multi-parameter sensing systems is crucial for advanced environmental and industrial monitoring.
• Ultra-weak fiber Bragg gratings (UFBGs) offer potential for increased sensor integration and multiplexing.

Purpose of the Study:

• To propose and experimentally demonstrate a multi-parameter measurement system utilizing an ultra-weak fiber Bragg grating (UFBG) array.
• To investigate the performance and multiplexing capabilities of the UFBG array for simultaneous measurement of multiple parameters.
• To address cross-sensitivity issues between temperature and other measured parameters.

Main Methods:

• Fabrication of an ultra-weak fiber Bragg grating (UFBG) array with ~0.04% reflectivity.
• Implementation of a time division multiplexing (TDM) interrogation technique using semiconductor optical amplifiers.
• Development of a uniform solution to decouple cross-sensitivities between temperature and target parameters (hydrogen, humidity, salinity).

Main Results:

• The UFBG array system demonstrated performance comparable to traditional FBG sensors.
• Experimental validation was performed on a 144-UFBG array for hydrogen, humidity, temperature, and salinity.
• The system showed significant superiority in multiplexing ability, with potential for thousands of sensors on a single fiber.

Conclusions:

• The proposed UFBG array system is a viable and high-performance solution for multi-parameter sensing.
• The TDM interrogation and cross-sensitivity management enable robust and accurate measurements.
• This technology holds promise for scalable, high-density sensor networks in diverse applications.