Flexible and Ultrathin Metal-Oxide Films for Multiresonance-Based Sensors in Plastic Optical Fibers

We have exploited a laser-based integration process of ultrathin metal-oxide (MO) films to improve the plasmonic effect in sensors based on D-shaped plastic optical fibers (POFs). More specifically, using MO films, performances surface plasmon resonance (SPR) phenomenon and lossy mode (LMR) can occur. Although role this kind materials has been already presented, when they are deposited as overlayer (upside thin metal film), we used different approach by depositing MOs, especially zirconium oxide (ZrO2) titanium (TiO2), flexible intermediate layers between exposed core POFs gold film. The layer is prepared from sol–gel solution, deep-UV laser curing allows us densify film tune refractive index, with room-temperature fully compatible polymer substrates. In preliminary step, carried out numerical results, transfer matrix formalism, predict SPR response. Subsequently, experimentally characterized developed sensor configurations. Numerical experimental results shown above all an enhancement performances, terms sensitivity, respect reference instead MOs. Moreover, some proposed configurations, together phenomenon, LMR was observed. It occurred wavelength range, for typical index range present considering receptors biochemical sensing applications. Therefore, both resonances (SPR LMR) could be several application fields.