Photonic crystals (PhCs) exhibit a strong confinement of light in a very small volume, providing local modes which are able to enhance the interaction of radiation with an analyte in an efficient optical sensing scheme. Over the years, the use of PhCs has therefore gone far beyond the realization of low-threshold lasers, low-loss resonators, optical switches, waveguides, and optical fibers, with innovative sensing designs for environmental monitoring, medical diagnosis, defense, and food quality control repeatedly envisaged (to name a few).

Si stima che circa un miliardo di persone nel mondo, specialmente nelle fasce di età più avanzate, soffrano di carenza o insufficienza di vitamina D, alle quali sono state associate diverse condizioni mediche, tra cui diabete, cancro, malattie cardiovascolari e autoimmuni.