Multi-modal transmission of microwaves through hole arrays.

The microwave transmission through hole arrays in thick metal plates for both large holes (cut-off below onset of diffraction) and small holes (cut-off above onset of diffraction) have been compared through both experiment and modelling. Enhanced transmission is in part mediated by the excitation of diffractively coupled surface waves. Large holes, with cut-off below the onset of diffraction (due to the hole periodicity), are able to support multiple modes in transmission when the depth of the holes is sufficient to support quantisation in the propagation direction. Small holes, with cut-off above the onset of diffraction however only support two coupled surface modes (symmetric and anti-symmetric) below diffraction.

Microwave transmission through a metal capped array of holes in a metal sheet.

The microwave response of a square array of "metal capped" holes in a metal sheet is explored both experimentally and numerically. Above each circular aperture are concentrically placed metallic discs, separated by a fraction of the wavelength, with discs having radii larger than the apertures. The volume bound by the overlap supports a family of resonances that mediate transmission with the fundamental resonant mode being a factor of ~2.3 lower in frequency than the bare aperture resonance.

Nano- and Micro-Auxetic Plasmonic Materials.

Plasmonic nanostructures with a negative Poisson ratio are demonstrated, having the unusual mechanical property of auxetics to expand laterally when being stretched. Using nanomembrane technology, auxetics are shrunk by orders of magnitude, giving simultaneous access to optical properties of plasmonic metamaterials, as well as auxetic mechanical properties on the nanoscale.

A magneto-electro-optical effect in a plasmonic nanowire material.

Electro- and magneto-optical phenomena play key roles in photonic technology enabling light modulators, optical data storage, sensors and numerous spectroscopic techniques. Optical effects, linear and quadratic in external electric and magnetic field are widely known and comprehensively studied. However, optical phenomena that depend on the simultaneous application of external electric and magnetic fields in conventional media are barely detectable and technologically insignificant. Here we report that a large reciprocal magneto-electro-optical effect can be observed in metamaterials. In an artificial chevron nanowire structure fabricated on an elastic nano-membrane, the Lorentz force drives reversible transmission changes on application of a fraction of a volt when the structure is placed in a fraction-of-tesla magnetic field. We show that magneto-electro-optical modulation can be driven to hundreds of thousands of cycles per second promising applications in magneto-electro-optical modulators and field sensors at nano-tesla levels.