Light-guiding Properties of Hollow-core Negative Curvature Fibers with Non-uniform Dielectric Capillaries in the Visible Spectrum

In this work, we investigate the effect of non-uniform dielectric capillary on the light-guiding characteristics of hollow-core negative curvature fibers, specifically the confinement loss and mode field diameter (MFD). Our findings suggest that this effect offers considerable flexibility in the guidance band, while maintaining a consistent MFD across various wavelengths. This enables precise adjustment of the guidance band of hollow-core negative curvature fibers based on the wavelength of light, while ensuring MFD stability. These results have potential applications in communication and optical fiber sensing.