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A Silicon-tipped Fiber-optic Sensing Platform with High Resolution and Fast Response
Published on: January 7, 2019
Optical fiber relative humidity sensor based on FBG incorporated thin-core fiber modal interferometer
Bobo Gu1, Mingjie Yin, A Ping Zhang
1Centre for Optical and Electromagnetic Research, State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou, China.
Optics Express
|March 4, 2011
Summary
A novel fiber-optic sensor utilizes a thin-core fiber modal interferometer with a fiber Bragg grating for accurate relative humidity (RH) sensing. This innovative sensor demonstrates high resolution and temperature compensation for reliable environmental monitoring.
Area of Science:
- Photonics and Sensing Technologies
- Materials Science and Nanotechnology
- Environmental Monitoring
Background:
- Fiber-optic sensors offer advantages in remote and harsh environment sensing.
- Relative humidity (RH) monitoring is crucial for various applications, including environmental control and industrial processes.
- Existing RH sensors face challenges with accuracy, response time, and temperature cross-sensitivity.
Purpose of the Study:
- To develop and characterize a new fiber-optic relative humidity (RH) sensor.
- To investigate the use of a thin-core fiber modal interferometer (TCFMI) combined with a fiber Bragg grating (FBG) for enhanced RH sensing.
- To evaluate the sensor's performance, including resolution, response linearity, reversibility, and temperature compensation.
Main Methods:
- Fabrication of a TCFMI sensor with an integrated FBG.
- Layer-by-layer deposition of poly (N-ethyl-4-vinylpyridinium chloride) (P4VP·HCl) and poly (vinylsulfonic acid, sodium salt) (PVS) for the sensing nanocoating.
- Characterization of the nanocoating using UV-vis absorption spectroscopy, quartz crystal microbalance (QCM), and scanning electron microscopy (SEM).
- Experimental testing of the sensor's response to RH variations at different temperatures.
Main Results:
- The sensor successfully detected relative humidity with a resolution of 0.78% over a wide RH range.
- The integrated FBG effectively compensated for temperature cross-sensitivity.
- The sensor exhibited a linear, fast, and reversible response to RH changes.
- Characterization confirmed the successful fabrication and properties of the sensing nanocoating.
Conclusions:
- The proposed fiber-optic RH sensor based on TCFMI and FBG is a promising technology for accurate and reliable humidity monitoring.
- The layer-by-layer deposited polymer coating provides effective RH sensing capabilities.
- The sensor's temperature compensation mechanism enhances its practical applicability in diverse environmental conditions.
