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E. Plum

Publications and source records attributed to E. Plum.

9 recordsLinked to original sources
arXiv2010

A combinatorial approach to metamaterials discovery

We report a high through-put combinatorial approach to photonic metamaterial optimization. The new approach is based on parallel synthesis and consecutive optical characterization of large numbers of spatially addressable nano-fabricated metamaterial samples (libraries) with quasi-continuous variation of design parameters under real manufacturing conditions. We illustrate this method for Fano-resonance plasmonic nanostructures arriving at explicit recipes for high quality factors needed for switching and sensing applications.

physics.optics↗
arXiv2010

Multi-fold Enhancement of Quantum Dot Luminescence in a Plasmonic Metamaterial

We report that hybridizing semiconductor quantum dots with plasmonic metamaterial leads to a multi-fold intensity increase and narrowing of their photoluminescence spectrum. The luminescence enhancement is a clear manifestation of the cavity quantum electrodynamics Purcell effect that can be controlled by the metamaterial's design. This observation is an essential step towards understanding loss compensation in metamaterials with gain media and for developing metamaterial-enhanced gain media.

physics.optics↗
arXiv2010

Asymmetric transmission: a generic property of lossy periodic interfaces

Asymmetric transmission of circularly polarized waves is a well-established property of lossy, anisotropic, two-dimensionally chiral patterns. Here we show that asymmetric transmission can be observed for oblique incidence onto any lossy periodically structured plane. Our results greatly expand the range of natural and artificial materials in which directionally asymmetric transmission can be expected making it a cornerstone electromagnetic effect rather than a curiosity of planar chiral metamaterials. Prime candidates for asymmetric transmission at oblique incidence are rectangular arrays of plasmonic spheres or semiconductor quantum dots, lossy double-periodic gratings and planar metamaterial structures.

physics.optics↗
arXiv2009

Terahertz metamaterial with asymmetric transmission

We show for the first time that a planar metamaterial, an array of coupled metal split-ring resonators with a unit cell lacking mirror symmetry, exhibits asymmetric transmission of terahertz radiation (0.25-2.5 THz) propagating through it in opposite directions. This intriguing effect, that is compatible with Lorentz reciprocity and time-reversal, depends on a directional difference in conversion efficiency of the incident circularly polarized wave into one of opposite handedness, that is only possible in lossy low-symmetry planar chiral metamaterials. We show that asymmetric transmission is linked to excitation of enantiomerically sensitive plasmons, these are induced charge-field excitations that depend on the mutual handedness of incident wave and metamaterial pattern. Various bands of positive, negative and zero phase and group velocities have been identified indicating the opportunity to develop polarization sensitive negative index and slow light media based on such metamaterials.

physics.optics↗
arXiv2009

Spectral collapse in ensembles of meta-molecules

We report on a new collective phenomenon in metamaterials: spectral line collapse with increasing number of the unit cell resonators (meta-molecules). Resembling the behaviour of exotic states of matter, such as Bose-Einstein condensates of excitons and magnons, this new effect is linked to the suppression of radiation losses in periodic arrays. We demonstrate experimentally spectral line collapse at microwave, terahertz and optical frequencies. It emerges as a universal and truly scalable effect underpinned by classical electromagnetic interactions between the excited meta-molecules.

physics.optics↗
arXiv2008

Planar metamaterial with transmission and reflection that depend on the direction of incidence

We report that normal incidence reflection and transmission of circularly polarized electromagnetic waves from and through planar split-ring metamaterials with chiral symmetry breaking depends on the incidence direction and handedness of circular polarization. The effect has a resonant nature and is linked to the lack of mirror-symmetry in the metamaterial pattern leading to a polarization-sensitive excitation of electric and magnetic dipolar responses in the meta-molecules.

physics.optics↗
arXiv2008

Optical Activity of Planar Achiral Metamaterials

We report that the classical phenomena of optical activity and circular dichroism, which are traditionally associated with chirality (helicity) of organic molecules, proteins and inorganic structures, can be observed in non-chiral artificial media. Intriguingly, our metamaterial structure yields exceptionally strong resonant optical activity, which also leads to the appearance of a backward wave, a characteristic sign of negative-index media.

physics.optics↗