Terahertz science and technology is a research area that has expanded rapidly in the past decade, with terahertz spectroscopy and imaging now becoming important tools in applications as diverse as nanotechnology and industrial quality control. The power of terahertz spectroscopy is based on the ability to generate coherent terahertz radiation and to detect its electric field as a function of ti...

In this paper we analyse the trade-offs for a terahertz imaging system and discuss implementation of a terahertz micro antenna array for imaging. We also describe applications of terahertz imaging and improvements in the signal processing. q 2000 Elsevier Science Ltd. All rights reserved.

Experimental investigations of ultrafast electro-optical properties in magnetic materials manifest their great potential for emerging spintronic optoelectronic devices. Here, using time-resolved terahertz emission spectroscopy, we construct a emitter consisting an ${\mathrm{Ir}\mathrm{Mn}}_{3}/\mathrm{Ni}\ensuremath{-}\mathrm{Fe}$ heterojunction. A femtosecond spin current pulse is generated th...

Emission of terahertz radiation is observed when surface plasmons are excited on a thin film of gold, in the Kretschmann geometry. When a hemicyanine-terminated alkanethiol self-assembled monolayer of thickness 1.2 nm is deposited on the gold film, stronger terahertz emission is observed. Our experimental results confirm that enhanced terahertz emission is possible from planar gold surfaces whe...

Using terahertz time domain spectroscopy we demonstrate tunable polarization rotation and circular dichroism in intrinsically non-chiral planar terahertz metamaterials without twofold rotational symmetry. The observed effect is due to extrinsic chirality arising from the mutual orientation of the metamaterial plane and the propagation direction of the incident terahertz wave.

Ultrafast charge and spin excitations in the elusive terahertz regime1,2 of the electromagnetic spectrum playa pivotal role in condensed matter3-13• The electric field of free-space terahertz pulses has provided a direct gateway to manipulating the motion of charges on the femtosecond timescale6-9 • Here, we complement this process by showing that the magnetic component of intense terahertz tra...

We demonstrate the construction of corrugated waveguides using stacked rings to propagate terahertz frequencies. The waveguide allows propagation of the same fundamental mode as an optical-fiber, namely, the HE(11) mode. This simple concept opens the way for corrugated wave-guides up to several terahertz, maintaining beam characteristics as for terahertz applications.

We suggest a mechanism by which a superradiant burst emerges from a subwavelength array of nonlinear classical emitters that are not initially synchronized. The emitters interact via the field of their common radiative response. We show that only if the distribution of initial phases is not uniform does a non-zero field of radiative response arise, leading to a superradiant burst. Although this...

Hydraulic impedance is a critical parameter for the operation of electrospray emitters, and for preventing flooding when spraying from arrays of emitters. Controlling flow rate by tuning the flow impedance allows accessing different operating modes, such as droplet, ionic, or pulsating. We report on a method to tailor the hydraulic impedance of micromachined capillary out-of-plane emitters with...

Plasmon resonance is expected to occur in metallic and doped semiconducting carbon nanotubes in the terahertz frequency range, but its convincing identification has so far been elusive. The origin of the terahertz conductivity peak commonly observed for carbon nanotube ensembles remains controversial. Here we present results of optical, terahertz, and direct current (DC) transport measurements ...