Highly photosensitive polymethyl methacrylate microstructured polymer optical fiber with doped core

Area of Science:

• Materials Science
• Optics and Photonics
• Polymer Chemistry

Background:

• Microstructured polymer optical fibers (MPOFs) offer unique light-guiding properties.
• Photosensitive materials are crucial for fabricating optical fiber devices like fiber Bragg gratings (FBGs).
• Traditional methods for doping optical fibers can be complex and may require index-compensating dopants.

Purpose of the Study:

• To fabricate a highly photosensitive MPOF using benzyl dimethyl ketal (BDK) as a dopant.
• To inscribe a fiber Bragg grating (FBG) within the fabricated MPOF.
• To demonstrate an efficient and advantageous doping method for photosensitive optical fibers.

Main Methods:

• Fabrication of a microstructured polymer optical fiber incorporating benzyl dimethyl ketal (BDK) as a dopant.
• Inscription of a fiber Bragg grating (FBG) within the BDK-doped MPOF using UV light.
• Characterization of the refractive index change and FBG transmission rejection.

Main Results:

• Achieved a significant refractive index change in the fiber core of at least 3.2×10⁻⁴.
• Successfully inscribed an FBG with a strong transmission rejection of -23 dB.
• Demonstrated a rapid inscription time of only 13 minutes for the FBG.
• The fabrication method allows doping without additional index-compensating agents.

Conclusions:

• A highly photosensitive MPOF doped with BDK has been successfully fabricated.
• The developed MPOF is suitable for rapid and efficient FBG inscription.
• This doping approach offers advantages over traditional methods for index-compensating step-index fibers.