Liquid-core, liquid-cladding photonic crystal fibers.

Area of Science:

• Photonics
• Materials Science
• Waveguide Optics

Background:

• Photonic crystal fibers (PCFs) offer unique light-guiding properties.
• Controlling light propagation within PCFs is crucial for various optical applications.
• Simultaneous filling of PCF core and cladding with liquids presents fabrication challenges.

Purpose of the Study:

• To demonstrate a novel technique for simultaneously filling the core and cladding of a PCF with distinct liquids.
• To create tunable liquid-core, liquid-cladding waveguides.
• To investigate the control over light guidance characteristics by selecting liquids and their refractive indices.

Main Methods:

• Experimental demonstration of a simple and novel filling technique for PCFs.
• Simultaneous insertion of two different liquids into the core and cladding regions of a PCF.
• Experimental and theoretical investigation of light confinement and guidance mechanisms.

Main Results:

• Successful creation of liquid-core, liquid-cladding waveguides.
• Tuning of core-cladding index difference by liquid selection to control the number of guided modes.
• Achieved single-mode guidance for a specific liquid combination.
• Observed transition from photonic bandgap to total internal reflection guidance based on index contrast and PCF length.

Conclusions:

• The developed technique enables the fabrication of versatile liquid-filled PCF waveguides.
• Precise control over optical properties, including modal behavior, is achievable through liquid selection.
• The study provides insights into light confinement phenomena in such engineered waveguides.