Subwavelength terahertz imaging via virtual superlensing in the radiating near field.

Imaging with resolutions much below the wavelength λ - now common in the visible spectrum - remains challenging at lower frequencies, where exponentially decaying evanescent waves are generally measured using a tip or antenna close to an object. Such approaches are often problematic because probes can perturb the near-field itself. Here we show that information encoded in evanescent waves can be probed further than previously thought, by reconstructing truthful images of the near-field through selective amplification of evanescent waves, akin to a virtual superlens that images the near field without perturbing it.

20 dB improvement utilizing custom-designed 3D-printed terahertz horn coupler.

Terahertz band is envisaged to provide substantially higher capacity and much lower latency for wireless communications in contrast to microwave frequencies. Moving to higher frequencies comes with its own unique challenges to be addressed, such as poor coupling efficiency from free space into and out of planar air-core waveguides. Here, we propose a framework for rapid design and low-cost fabrication of terahertz horn couplers.

Towards subdiffraction imaging with wire array metamaterial hyperlenses at MIR frequencies.

We describe the fabrication of metamaterial magnifying hyperlenses with subwavelength wire array structures for operation in the mid-infrared (around 3 μm). The metadevices are composed of approximately 500 tin wires embedded in soda-lime glass, where the metallic wires vary in diameter from 500 nm to 1.2 μm along the tapered structure.

Fano enhancement in hybrid plasmonic nanoresonator.

Combining the advantages of photonics (low loss) and plasmonics (high field confinement), while mitigating their respective drawbacks, can greatly enhance the light-matter interaction efficiency. Here we make use of a time-dependent coupled mode theory in order to theoretically model the excitation of a plasmonic nanoantenna via a photonic resonator. We show that including the light source-nanoantenna direct coupling substantially enhances the overall coupling efficiency, maintaining the same input power.

Stimulated Brillouin scattering enhancement in silicon inverse opal waveguides.

Silicon is an ideal material for on-chip applications, however its poor acoustic properties limit its performance for important optoacoustic applications, particularly for stimulated Brillouin scattering (SBS). We theoretically show that silicon inverse opals exhibit a strongly improved acoustic performance that enhances the bulk SBS gain coefficient by more than two orders of magnitude. We also design a waveguide that incorporates silicon inverse opals and which has SBS gain values that are comparable with chalcogenide glass waveguides.