A reliable, sensitive and fast optical fiber hydrogen sensor based on surface plasmon resonance

Area of Science:

• Optoelectronics
• Nanomaterials
• Chemical Sensing

Background:

• Surface Plasmon Resonance (SPR) sensors are valuable for detecting chemical species.
• Fiber optic sensors offer advantages like remote and multi-point sensing capabilities.
• Hydrogen sensing is critical for safety and industrial process monitoring.

Purpose of the Study:

• To experimentally demonstrate a novel SPR fiber optic sensor for hydrogen sensing.
• To investigate the sensor's performance using wavelength modulation for enhanced stability.
• To optimize the sensor's sensitivity and selectivity for hydrogen detection.

Main Methods:

• Fabrication of a fiber optic sensor with a multilayer structure (Au/SiO2/Pd) on a multimode fiber core.
• Utilizing wavelength modulation for SPR measurements to ensure insensitivity to intensity fluctuations.
• Systematic variation of Palladium (Pd) thickness to determine optimal sensitivity and selectivity.

Main Results:

• The SPR fiber optic sensor demonstrated effective hydrogen detection.
• Optimal sensitivity and selectivity were achieved with a Pd thickness of 3.75 nm.
• The sensor accurately measured hydrogen concentrations from 0.5 to 4% H2 in Ar.
• A rapid response time of less than 15 seconds was observed.

Conclusions:

• The developed SPR fiber optic sensor based on wavelength modulation is a promising technology for hydrogen sensing.
• The sensor's design provides robustness against intensity fluctuations and enables remote and multi-point sensing.
• The optimized sensor exhibits high sensitivity and selectivity for hydrogen detection within a specific concentration range.