Observation of optical azimuthons

We observe experimentally optical azimuthons, a generic class of ring-shaped localised spiralling beams with azimuthal modulation, carrying phase dislocation in self-focusing nonlinear media. We observe three- and four-lobe azimuthons in 87Rb vapours and demonstrate their anomalous rotation controlled by the input phase distribution

Generation and Near-Field Imaging of Airy Surface Plasmons

We demonstrate experimentally the generation and near-field imaging of nondiffracting surface waves, plasmonic Airy beams, propagating on the surface of a gold metal film. The Airy plasmons are excited by an engineered nanoscale phase grating, and demonstrate significant beam bending over their propagation. We show that the observed Airy plasmons exhibit self-healing properties, suggesting novel applications in plasmonic circuitry and surface optical manipulation

Plasmonic Colour Filters Based on Coaxial Holes in Aluminium

Aluminum is an alternative plasmonic material in the visible regions of the spectrum due to its attractive properties such as low cost, high natural abundance, ease of processing, and complementary metal-oxide-semiconductor (CMOS) and liquid crystal display (LCD) compatibility. Here, we present plasmonic colour filters based on coaxial holes in aluminium that operate in the visible range. Using both computational and experimental methods, fine-tuning of resonance peaks through precise geometric control of the coaxial holes is demonstrated. These results will lay the basis for the development of filters in high-resolution liquid crystal displays, RGB-spatial light modulators, liquid crystal over silicon devices and novel displays.This research was supported by a UM Interdisciplinary Seed Grant and the McKenzie Fellowship Scheme of The University of Melbourne. AR acknowledges ARC support through Grant DP110100221. RRU acknowledges ARC support through DP170100363

Dual-channel spontaneous emission of quantum dots in magnetic metamaterials

Metamaterials, artificial electromagnetic media realized by subwavelength nano-structuring, have become a paradigm for engineering electromagnetic space, allowing for independent control of both electric and magnetic responses of the material. Whereas mo

Two Methods to Achieve the Tunability of Optical Fishnet Metamaterials

In this work we propose two ways of tuning of the optical properties of a fishnet metamaterial infiltrated by liquid crystal. The first method is to control the hole mode of the structure via the reorientation of the liquid crystal molecules. We show that in this case the system is mainly sensitive to the refractive index change occurring inside the holes. The second technique is to tune surface-plasmon polariton modes. In this instance the structure becomes sensitive mainly to the refractive index change at the metal-liquid crystal interface. We demonstrate that controlling the surface modes one can achieve higher variation of the effective index (more than 300 times index enhancement), however transmission in such a system is lower than for the case of the hole mode control

Influence of the substrate on negative index fishnet metamaterials

We analyze numerically the influence of the dielectric substrate on the optical response and effective macroscopic parameters of fishnet metamaterials. We show that the substrate can suppress the region of the negative refractive index due to the weakening of the gap plasmon associated with the magnetic resonance of the structure. We also demonstrate that the effect of substrate vanishes when the number of the functional layers increases

Topology of iso-frequency surfaces of multilayer fishnet metamaterials

We study the anisotropic optical properties of multilayer fishnet metamaterials, showing that they exhibit hyperbolic dispersion. This unique magnetic form of hyperbolic media is promising for the control of spontaneous emission

Experimental reconstruction of nonlocal response of thermal nonlinear optical media

We study experimentally and theoretically the nonlocal response of a medium with thermal nonlinearity and show that despite its inherently infinite range it can be accurately characterized by a well-defined nonlocal response function. We retrieve the shape of this function and analyze its transformation with the change of boundaries

Control of Airy Plasmon Trajectories in Linear Gradient Systems

In this work we demonstrate experimentally the manipulation of Airy surface plasmon beams in a linear potential system. We used a negative-tone grey-scale electron beam lithography to fabricate plasmonic structures with a dielectric ramp which provides