Fabricating Nanoporous Silica Structure on D-Fibres through Room Temperature Self-Assembly

Area of Science:

• Materials Science
• Optical Engineering
• Nanotechnology

Background:

• Modified Chemical Vapour Deposition (MCVD) is used to fabricate preforms for D-shaped optical fibres (D-fibres).
• Self-assembling silica nanoparticles offer potential for novel optical fibre coatings.

Purpose of the Study:

• To investigate room temperature deposition of silica nanoparticles onto D-fibres.
• To evaluate different deposition techniques for uniform nanoparticle coating.
• To explore methods for assessing nanoparticle layer quality.

Main Methods:

• Fabrication of D-fibres using MCVD.
• Room temperature dip-and-withdraw deposition of silica nanoparticles.
• Utilizing a D-fibre inner cladding protrusion to prevent drying-induced fractures.
• Characterization using thin film interference, Scanning Electron Microscopy (SEM), and fluorescence imaging with Rhodamine B.

Main Results:

• Vertical dip-and-withdraw resulted in tapered nanoparticle layers (>0.85 surface coverage at one end).
• Horizontal dip-and-withdraw produced uniform nanoparticle layers across the D-fibre core.
• A D-fibre inner cladding protrusion effectively mitigated drying-induced fracturing.
• Fluorescence imaging provided a rapid, qualitative assessment of nanoparticle coverage, complementing SEM.

Conclusions:

• Horizontal dip-and-withdraw is a viable method for uniform silica nanoparticle coating on D-fibres.
• Fluorescence imaging offers a practical approach for quick evaluation of nanoparticle coatings.
• The developed technique holds promise for functionalizing optical fibres.