(Elsevier, 2024) Gallego Martínez, Elieser Ernesto; Ruiz Zamarreño, Carlos; Matías Maestro, Ignacio; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
This work presents an optical sensor for ultraviolet radiation (UV) detection, based on the combined effects of
Lossy Mode Resonance (LMR) in the mid infrared (MIR) spectral region and the photoisomerization of a polymeric dye coating. LMR was obtained by means of a sputtered SnO2 thin film on a tetrafluoroethylene-perfluoro
(or alkoxy Vinyl Ether, PFA) substrate, along with a photo sensitive coating based on poly R-478. Obtained
devices shown response and recovery times of 12 and 43 s, respectively, for an UV excitation of 71 mW at 365
nm. Sensitivity as a function of the excitation wavelength was studied with the highest value of 26 nm/mW
obtained at 280 nm. For this excitation wavelength, the limit of detection (LoD) obtained was 0.024 mW. Four
different excitation wavelengths were used to cover all UV regions (280, 310, 365 and 395 nm). All measurements were performed at room temperature and humidity (25 ¿C ± 1 ¿C and 13% R.H. ± 2% R.H. respectively).
As far as we know, it is the first time that the LMR effect has been recognized in combination with a photoisomerization process.
