The study of lightning phenomena will be carried out by a dedicated instrument, the lightning imager, that will make use of narrow-band transmission filters for separating the Oxygen emission lines in the clouds, from the background signal. The design, manufacturing and testing of these optical filters will be described here.
Fishnet metamaterials (MM) conceived for optical coating applications have been simulated for metal-dielectric-metal structures based on silver and oxides. Preliminary experimental results on large-scale fabrication are presented here for alumina-silver based structures. Millimeter-size MM layers have been realized by combination of r.f. sputtering and focused-ion-beam writing.
Many fields of high technology take advantage of conductor-dielectric interface properties. Deeper knowledge of
physical processes that determine the optical response of the structures containing metal-dielectric interfaces is important
for improving the performance of thin film devices containing such materials.
Here we present a study on optical properties of several ultrathin metal oxides deposited over thin silver layers. Some
widely used materials (Al2O3, SiO2, Y2O3, HfO2) were selected for deposition by r.f. sputtering, and the created metal-dielectric
structures with two of them, alumina and silica, were investigated in this work using attenuated total reflectance
(ATR) technique and by variable-angle spectroscopic ellipsometry (VASE). VASE was performed with a help of a
commercial ellipsometer at various incident angles and in a wide spectral range. A home-made sample holder
manufactured for WVASE ellipsometer and operational in Otto configuration has been implemented for angle-resolved
and spectral ATR measurements. Simultaneous analysis of data obtained by these two independent techniques allows
elaboration of a representative model for plasmonic-related phenomena at metal-dielectric interface. The optical constants
of the interface layers formed between metal and ultrathin oxide layers are investigated. A series of oxides chosen for this
study allows a comparative analysis aimed for selection of the most appropriate materials for different applications.