Manifestation of Planar and Bulk Chirality Mixture in Plasmonic Λ‑Shaped Nanostructures Caused by Symmetry Breaking Defects

We report on the coexistence of planar and bulk chiral effects in plasmonic Λ-shaped nanostructure arrays arising from symmetry breaking defects. The manifestation of bi- (2D) and three-dimensional (3D) chiral effects are revealed by means of polarization tomography and confirmed by symmetry considerations of the experimental Jones matrix. Notably, investigating the antisymmetric and symmetric parts of the Jones matrix points out the contribution of 2D and 3D chirality in the polarization conversion induced by the system whose eigenpolarizations attest to the coexistence of planar and bulk chirality. Furthermore, we introduce a generalization of the microscopic model of Kuhn, yielding to a physical picture of the origins of the observed planar chirality, circular birefringence, and dichroism, theoretically prohibited in symmetric Λ-shaped nanostructures

Polarization-Controlled Confined Tamm Plasmon Lasers

In this paper we report on the evidence of polarized and spatially localized emission of a Tamm laser. The polarized emission results from an anisotropic three-dimensional confinement of Tamm plasmon modes at the interface between an active semiconductor distributed Bragg reflector and a silver thin-film. The spatial confinement is achieved by patterning microrectangles with an aspect ratio of 2 in the top metallic layer. This geometrical birefringence is observed to split the fundamental confined Tamm mode into two modes, which result to be orthogonally polarized along the two sides of the structure. We measure a wavelength splitting between the nondegenerate modes of ∼0.2 nm, which turns out to be in good agreement with numerical calculations. This weak splitting, together with the strong wavelength dependence of the buried quantum wells gain curve, allows us to demonstrate the existence of a highly linearly polarized laser emission at ∼850 nm. By controlling the detuning between the confined Tamm modes and the gain curve, we report on a maximum degree of linear polarization in excess of 90%

Generation and Spatial Control of Hybrid Tamm Plasmon/Surface Plasmon Modes

In this Letter we experimentally demonstrate the coupling between Tamm plasmon and surface plasmon modes in a metal/semiconductor integrated microstructure. The Tamm plasmon mode is excited by the photoluminescence of quantum dots grown in the top part of a dielectric Bragg mirror covered by a silver layer. The hybrid nature of such a Tamm plasmon/surface plasmon mode is demonstrated by the observation of a spatial beating along the propagation. Experimental results are in very good agreement with numerical calculations. We show how such a structure can be used and further optimized to create surface plasmons through electrical pumping. These results pave the way to a new generation of hybrid metal/semiconductor integrated optical devices for both energy-sensitive surface detection and electrical excitation of surface plasmons