Spectroscopic Characteristics of Three Dimensional Split-Ring Resonator Arrays at Terahertz Frequencies.

In this work, three-dimensional, stacked arrays of subwavelength, square, dual, concentric split ring resonators exhibiting characteristics at the Terahertz frequencies have been designed, simulated, and fabricated through a photolithographic lift-off process and electron beam evaporation metal deposition. Characterization of the split-ring resonator arrays was performed by transmission mode Terahertz time domain spectroscopy. The effects of the split-ring resonator unit cell spatial dimensions on resonant absorption frequencies and relative absorption strength are investigated as well as effects from the addition of a dielectric spacing layer and additional split-ring resonator layer.

Observation of hydrofluoric acid burns on osseous tissues by means of terahertz spectroscopic imaging.

Terahertz technologies have gained great amount of attention for biomedical imaging and tissue analysis. In this study, we utilize terahertz imaging to study the effects of hydrofluoric acid on both compact bone tissue and cartilage. We compare the differences observed in the exposure for formalin fixed and raw, dried, tissue as well as those resulting from a change in hydrofluoric (HF) concentration.

Design and analysis of perfect terahertz metamaterial absorber by a novel dynamic circuit model.

Metamaterial terahertz absorbers composed of a frequency selective layer followed by a spacer and a metallic backplane have recently attracted great attention as a device to detect terahertz radiation. In this work, we present a quasistatic dynamic circuit model that can decently describe operational principle of metamaterial terahertz absorbers based on interference theory of reflected waves. The model comprises two series LC resonance components, one for resonance in frequency selective surface (FSS) and another for resonance inside the spacer.

High resolution, two-dimensional image mapping of ZnO nanowires by confocal microphotoluminescence and microraman spectroscopy.

High-quality ZnO nanowires were synthesized using both Au catalysts and ZnO seeds by chemical vapor depositionon basal plane sapphire substrates. The nanowires were hexagonal and aligned with their c-axis closely perpendicular to the sapphire substrate surface. The structural characteristics of the nanowiresgrown using the different catalysts/seeds were compared using scanning electron microscopyand X-ray diffraction.