Nanoplasmonics and surface enhanced spectroscopy

Active hybrid plasmon-photon sensors based on surface-barrier semiconductor structures with photonic crystals terminated by continuous metallic films
Korovin A.V.1, Sosnova M.V.1
1 V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine. Prospect Nauki, 41, Kiev-03028
E-mail: korovin@isp.kiev.ua

Recently, new concepts for mixing the properties of photonic and plasmon nanostructures for nanomaterials with controlled optical properties are being actively developed for use in sensors, photovoltaics, etc. The defective modes (DM) appear in the systems with periodicity violation in photonic crystals (PhC). For example, the excitation of the defect mode of PhC can be realized in PhC terminated by a metallic film [1]. The presence of a metal film provides excitation of surface plasmon-polariton (SPP), which is a nonradiative mode in contrast to radiative DM. The interaction between DM and SPP has been demonstrated in a system of periodically profiled metal film on a semiconductor substrate with quasi-1D PhC on the front surface of a metal film [2]. This interaction leads to the splitting of the dispersion of DM and SPP and the improved spatial localization of the SPP due to the hybridization of these modes. However, the presence of a profiled surface necessary for excitation of SPP in such system leads to an increase of surface recombination at the metal-semiconductor interface. This report presents the results of numerical modeling of a flat metal film deposited on a semiconductor substrate with a quasi 2D PhC on the front surface of the metal film. The quasi 2D PhC is formed by a multilayer dielectric Bragg mirror with a periodic system of etched slits that allow the detectable substance to penetrate the front surface of the metal film when such system is used as an active sensor. Effective hybridization of SPP and DM of 2D PhC was shown with the obtained sensitivity of such hybrid modes to changes in the refractive index of the 2D PhC slits commensurate with the commercial SPP sensors.
1.	Korovin A.V. and Romanov S. Unconventional optical Tamm states in metal-terminated three-dimensional photonic crystals // Phys Rev B.-2016.-93.-P. 115440-1-10.
2.	Sosnova M.V. et al., Hybridization of Surface Plasmon Polariton and Photonic Crystal Modes in Bragg Mirror with Periodically Profiled Metal Film // Nanoscale Research Letters.-2016.-11.-P. 144-1-7.