Bragg grating in a flexible and stretchable coreless polymer optical fiber.

Area of Science:

• Materials Science
• Optical Engineering
• Sensor Technology

Background:

• Traditional silica fiber Bragg gratings (FBG) have limitations in flexibility and strain range.
• Developing novel FBG platforms is crucial for advanced sensing applications.

Purpose of the Study:

• To propose and demonstrate FBG fabrication in a flexible and stretchable coreless polymer optical fiber.
• To evaluate the sensing performance of the polymer FBG for strain, temperature, and humidity.

Main Methods:

• Fabrication of FBG using femtosecond laser direct writing and slit beam shaping in a polydimethylsiloxane (PDMS) polymer optical fiber.
• Experimental characterization of the FBG's response to strain, temperature, and humidity.

Main Results:

• The fabricated polymer FBG demonstrated a large strain measurement range.
• A blueshift response to temperature was observed, indicating temperature sensing capability.
• Low humidity sensitivity was achieved due to the polymer's low water vapor permeability.

Conclusions:

• The proposed PDMS-based FBG offers significant advantages over traditional silica FBGs for strain and temperature sensing.
• The unique sensing properties make it suitable for applications requiring flexibility and robustness.
• This work opens new avenues for polymer optical fiber sensors in harsh environments.