Aug 13 2019
A research team led by Professor Myakzyum Salakhov has been analyzing the problem of optical states in plasmonic-photonic crystals (PPCs). The team mostly includes young researchers, some of whom started contributing to the study during their student years.
Schemes of PPC with equal effective refractive index and structure period. (a) 1D PPC and (b) 3D opal-like PPC. (Image credit: Kazan Federal University)
According to First Category Engineer Artyom Koryukin, the study is dedicated to modeling light transmission throughout the photonic crystals with a continuous gold layer placed on their surface. Photonic crystals block a specific wavelength, or color, of light. This is known as the photonic bandgap, the light wavelength range at which propagation through a crystal is complicated.
By contrast, PPCs allow the light of a specific wavelength to pass through this photonic bandgap. However, the drawback of 3D opal-like PPCs (OLPPCs) is that they block the light of particular wavelengths.
As part of the study, conditions are defined for the propagation of a light beam with the photonic bandgap’s wavelength and specific polarization through an OLPPC. Different types of PPCs were modeled to realize this objective. The main conditions to allow the passage of such a beam are the continuity of the gold layer with approximately 40 nm thickness as well as the use of light with polarization.
The optical Tamm states are excited when light is transmitted across a PPC. 1D PPC includes light transmission pass bands within the photonic bandgap in both polarizations. By contrast, 3D PPCs do not include light transmission pass bands within the photonic bandgap due to a non-continuous gold layer (shaped like separate nano-crescents or nano-caps on a PPC’s surface).
Therefore, the used OLPPCs possess this exclusive feature—they include a light transmission pass band within the photonic bandgap with specific polarization caused by the excitation of the hybrid mode of the optical states. It is possible to use the OLPPCs including the hybrid mode of the optical states in high-polarization-sensitive sensors.
We assume that the hybrid mode can be useful for improving the control of light in PPCs. New types of resonators based on OLPPCs can be used for the strong interaction of light and matter.
Artyom Koryukin, First Category Engineer, Kazan Federal University
The team intends to theoretically describe the model of such processes. Moreover, they plan to determine effective applications for OLPPCs, for example, strong light-matter interactions with a single-photon source.