Advanced Optical Materials

A double-layer bi-anisotropic metamaterial is demonstrated, which exhibits strong asymmetric polarization rotation of two orthogonal linear polarizations around 0.53 THz. The application of the proposed metamaterial working as a controlled-NOT gate is further exploited. Such a polarization processor's architecture provides an effective path for the development of terahertz polarization control and future optical supercomputing technology.

A flexible, fully solution processed, nanocomposite substrate based on considerations of surface conductivity, microcavity tuning, and internal light scattering is able to outcouple both the waveguide and the substrate modes. With enhanced light outcoupling, white organic light-emitting diodes subsequently fabricated on the nanocomposite substrates demonstrate performance metrics of 107 lm W⁻¹ power efficiency and 49% external quantum efficiency at 1000 cd m⁻².

A rigorous optical analysis of methylammonium lead triiodide perovskite solar cells is reported. Accurate optical constants are determined by fitting ellipsometry and spectrophotometry data. Transfer-matrix-based simulations of several full solar cells show excellent agreement with experimental spectrophotometry data. The impact of perovskite surface roughness is highlighted, and the optical losses relevant for single-junction and perovskite/Si multijunction solar cells are quantified.

The spatial distribution of hot carriers in a plasmonic nanorod metamaterial can be designed by controlling geometrical parameters of the metamaterial for a given wavelength of excitation light. The inhomogeneous electron temperature distribution in plasmonic nanorods determines stronger third-order nonlinearity and faster nonlinear dynamics of metamaterials, governed by local dynamics of hot carries in plasmonic components.

Two classes of strongly emitting thermally activated delayed fluorescence dyes show tunable photophysical properties and unmatched temperature sensitivities in self-referenced lifetime mode. They are highly promising for preparation of optical thermometers in different formats including planar foils, fiber-optic sensors, and nanoparticles. Incorporated in gas-permeable matrixes, these readily available purely organic dyes are also suitable for optical oxygen sensing.