Angularly Cascaded Long-Period Fiber Grating for Curvature and Temperature Detection.

Area of Science:

• Fiber optics and sensing technologies
• Optical physics and instrumentation
• Materials science for sensor fabrication

Background:

• Long-period fiber gratings (LPFGs) are established optical sensing elements.
• Dual-parameter sensing is crucial for accurate environmental monitoring.
• Existing curvature sensors often lack simultaneous temperature compensation.

Purpose of the Study:

• To propose and demonstrate a high-sensitivity curvature sensor with dual-parameter measurement capability.
• To investigate the performance of an angularly cascaded long-period fiber grating (AC-LPFG) for simultaneous curvature and temperature sensing.
• To highlight the potential of AC-LPFG sensors in engineering applications.

Main Methods:

• Fabrication of an AC-LPFG sensor using a deep ultraviolet laser and amplitude-mask.
• Experimental setup for simultaneous measurement of curvature and temperature.
• Analysis of resonant peak wavelength shifts in response to applied curvature and temperature changes.

Main Results:

• Successful demonstration of an AC-LPFG sensor capable of simultaneous curvature and temperature measurement.
• Observed opposite wavelength shifts of two resonant peaks with increasing curvature.
• Achieved a maximum curvature sensitivity of 16.392 nm/m^-1.

Conclusions:

• The proposed AC-LPFG sensor enables simultaneous, high-sensitivity measurement of curvature and temperature.
• The sensor exhibits significant potential for various engineering applications due to its dual-parameter capability, high sensitivity, and cost-effectiveness.
• This work advances fiber optic sensing for complex environmental monitoring scenarios.