Synthesis and characterization of titanium nitride thin films for enhancement and localization of optical fields

© 2018 Elsevier B.V. Emerging plasmonic materials are an essential driving factor of the ongoing progress towards the empowering of photonic devices functionalities and performance improvement. Transition metal nitrides, being refractory metals with tunable optical properties, are prominent representatives of alternative plasmonic materials. Recent intensive examination of linear and nonlinear optical parameters of metal nitrides has revealed TiN to be a promising media for metal-based optics. Another distinctive feature of TiN is its Raman activity. In contrast to Raman-silent metals, TiN-based structures enable nonlinear light frequency conversion not only to even and odd harmonics, but also to Raman-shifted modes. Moreover, the threshold of the underlying stimulated Raman scattering (SRS) effect in these structures could be greatly reduced by appropriate geometry and material design. Here we experimentally investigate the effect of structure and composition of TiN on its optical properties, such as dielectric permittivity and third-order Raman susceptibility. A special attention is given to synthesis and characterization of TiN thin films suitable for plasmon-assisted localization and amplification of optical signals