Refractometric sensor based on a phase-shifted long-period fiber grating.

Area of Science:

• Fiber optic sensing
• Optical metrology
• Material science

Background:

• Long-period fiber gratings (LPFGs) are widely used for sensing applications.
• Traditional LPFG sensors often employ a transmission configuration.
• Optimizing LPFG sensor performance for high-resolution measurements remains an active research area.

Purpose of the Study:

• To investigate the performance of a phase-shifted long-period fiber grating (PS-LPFG) refractometric sensor.
• To compare the performance of transmission and reflective configurations for refractive index measurements.
• To assess the suitability of the developed sensor for demanding applications like salinity monitoring.

Main Methods:

• Fabrication of a PS-LPFG using electric-arc discharges.
• Experimental setup for measuring refractive index in both transmission and reflective modes.
• Analysis of sensor performance metrics, including resolution and sensitivity.

Main Results:

• The reflective configuration of the PS-LPFG sensor exhibited enhanced performance compared to the transmission configuration.
• Higher resolution in refractive index measurements was achieved with the reflective topology.
• The sensor demonstrated potential for accurate water salinity level determination.

Conclusions:

• The reflective PS-LPFG sensor offers a significant improvement over conventional transmission-based LPFG sensors.
• The developed sensor architecture is robust and suitable for high-precision refractive index sensing.
• This technology holds promise for real-world applications requiring sensitive environmental monitoring.