Towards Versatile Folded Microfibers: Folded versus Straight Configuration on Hydrophilic and Hydrophobic Substrates

On-fiber microstructures are favorable platforms for sensing in aqueous environments. We suggest and demonstrate two deployment schemes of microstructured fibers: folded configuration intended for remote sensing, and straight configuration on either hydrophilic or hydrophobic substrate, the latter of which is useful in packaged geometries. The persistent detection of NIR light transmission resonances in the presence of volatile liquid capabilities are experimentally demonstrated. We present numerical results on the photonic transmission in microknot resonators with different contact coupling area geometries and refractive index variations. A recipe for the experimental realization of a significant Q-factor increase in microknot resonators is also prescribed.