Thermo-plasmonic lab-on-fiber optrodes

The thermoplasmonic effect causing the local overheating in nanostructured metallic substrates has been recently recognized as an intriguing technological tool for the development of light-controlled active micro and nano systems. Here, we present a study of thermoplasmonic effect in Lab-on-Fiber devices, consisting in nanostructured gold layers directly integrated onto the cleaved facet of an optical fiber tip. We analyze the effect of the metallic nanostructure parameters on the temperature distribution under different (in-fiber) illumination conditions. Heating and cooling temporal dynamics are also investigated. At the steady state, a linear relationship between input optical power and temperature with a linear coefficient in the order of 10 °C/mW is found. All the experimental results are in good agreement with numerical simulations based on a finite element method. Our findings lay the groundwork for the development of light triggered active Lab-on-Fiber probes, merging the unique characteristics of the optical fiber platform and the enormous potentiality offered by thermoplasmonics.