Titanium and Nickel as alternative materials for mid Infrared Plasmonic

Finding suitable materials with low Drude losses for plasmonic applications at mid-infrared wavelengths is challenging. Highly doped Germanium and Germanium Tin alloys have been investigated to that end but are difficult to utilize at wavelengths closer to the near infrared region. In this work, we present results on the fabrication and optical characterization of Titanium and Nickel comb antennas. Extinction spectra were obtained via Fourier Transform Infrared (FTIR) Spectroscopy and verified via Finite Difference Time Domain (FDTD) simulation. The measured spectra show distinct extinction peaks in the range between 4 μm and 11 μm which can be correlated to a plasmonic mode forming at the antenna substrate interface showing that it is possible to excite localized plasmonic modes at the interface between such antennas and a Silicon substrate.