Speaker
Description
We present a novel UV photon detection method using ZnO/metal thin film architecture operated under surface plasmon resonance (SPR) conditions. Here, we couple a 633 nm probe light to the ZnO/metal thin film via the Kretschmann configuration to excite surface plasmons at the metal-dielectric interface. The reflectance of the probe light under SPR is utilized as the detection signal. The reflectance of the 633 nm probe light is expected to change due to the variations in the refractive index of the ZnO thin film as a result of the absorption of the UV photons and the subsequent creation of the photoinduced charge carriers. The reflectance is also expected to change due to the modulation of the SPR induced field at the metal-dielectric interface as result of the electric field screening by the creation and transport of the photoinduced charges. For the fabrication of the SPR-based detection devices, COMSOL Multiphysics simulations were utilized to optimize the film thicknesses of the ZnO/metal layers to produce the sharpest SPR curve for a 633 nm light with maximum loss in reflectivity at resonance. Preliminary results from our prototype detectors show that appreciable change in intensity of the reflected 633 nm from the metal-dielectric interface can be detected as the UV light is absorbed. We will discuss the utility of such an optical readout methodology for the detection of the scintillation VUV photons produced in liquid noble detectors.
