Akademik Veri Yönetim Sistemi
4th International Congress of Engineering and Natural Sciences Studies, Ankara, Türkiye, 24 - 25 Mayıs 2024, ss.165
Transition metal nitrides such as titanium nitride are materials that exhibit less optical loss due to their non-metallic nature, yet they can provide strong optical resonances due to their plasmonic characteristics. Titanium nitride-based nanoantennas designed in different geometries can also exhibit various electromagnetic phases. These properties make them suitable for use in metasurface designs serving applications such as focusing and beam splitting. In this context, the interface phase distribution required for a metasurface design capable of reflecting at 30 degrees in the direction of the incident plane at the operating wavelength of 1550 nm is determined. For this phase distribution, titanium nitride nanoantenna set with 18 different phase values in the range of 0-2π are numerically designed in various geometries. The dispersive dielectric permittivity data for titanium nitride nanoantennas are obtained from ellipsometric data of a titanium nitride film deposited at 800°C, using the Drude-Lorentz model. For numerical analysis, Finite Difference Time Domain Method is employed. The periodic arrangements of each antenna are individually analyzed, and the phase values created by these antennas are determined using field distribution monitors. For deflective metasurfaces, a specific interface phase distribution is present depending on the desired deflection angle. Each nanoantenna designed for efficient beam deflection must provide this phase distribution with the highest resolution. In this context, the aperiodic arrangement of these antennas on the interface is engineered taking into account the phase distribution of the relevant deflective metasurface. Keywords: Transition metal nitrides, metasurface, beam deflection, linear phase distribution