Related papers: A new artificial material approach for flat THz fr…
Diffractive/refractive optics, such as Phase Fresnel Lenses (PFL's), offer the potential to achieve excellent imaging performance in the x-ray and gamma-ray photon regimes. In principle, the angular resolution obtained with these devices…
The advancement of 3D-printing opens up a new way of constructing affordable custom terahertz (THz) components due to suitable printing resolution and THz transparency of polymer materials. We present a way of calculating, designing and…
Photosensitive materials with ever-improving properties are of great importance for optical and photonics applications. Additionally, they are extremely useful for designing components for neutron optical devices. We provide an overview on…
We analyze the use of layered superconductors as anisotropic metamaterials. Layered superconductors can have a negative refraction index in a wide frequency range for arbitrary incident angles. Indeed, low-Tc (s-wave) superconductors allow…
THz time-domain spectroscopy in transmission mode was applied to study dry and wet drawing inks. In specific, cochineal-, indigo- and iron-gall based inks have been investigated; some prepared following ancient recipes and others by using…
In this letter, we propose hybrid metal-dielectric waveguides coupled to 2D materials that provide strong light-matter interaction at THz frequencies. We investigate the properties of the fundamental propagating modes and show that the…
We demonstrate a practical scalable approach to the fabrication of tunable metamaterials. Designed for THz wavelengths, the metamaterial is comprised of polyurethane filled with an array of indium wires using the well-established fiber…
Gradient index sonic lenses based on two-dimensional sonic crystals are here designed, fabricated and characterized. The index-gradient is achieved in these type of flat lenses by a gradual modification of the sonic crystal filling fraction…
Among its many outstanding properties, graphene supports terahertz surface plasma waves -- sub-wavelength charge density oscillations connected with electromagnetic fields that are tightly localized near the surface[1,2]. When these waves…
We demonstrate efficient terahertz (THz) modulation by coupling graphene strongly with a broadband THz metasurface device. This THz metasurface, made of periodic gold slit arrays, shows near unity broadband transmission, which arises from…
A multiple-graphene-layer (MGL) structure with a stack of GLs and a highly conducting bottom GL on SiC substrate pumped by optical radiation is considered as an active region of terahertz (THz) and far infrared (FIR) lasers with external…
Surface plasmons in graphene may provide an attractive alternative to noble-metal plasmons due to their tighter confinement, peculiar dispersion, and longer propagation distance. We present theoretical studies of the nonlinear difference…
Plasmons, collective oscillations of electron systems, can efficiently couple light and electric current, and thus can be used to create sub-wavelength photodetectors, radiation mixers, and on-chip spectrometers. Despite considerable…
Non-destructive testing is an important technique for detecting defects in multi-layer materials, enabling the evaluation of structural integrity without causing damage on test materials. Terahertz time-domain spectroscopy (THz-TDS) offers…
As we read this text, our eyes dynamically adjust the focal length to keep the line image in focus on the retina. Similarly, in many optics applications the focal length must be dynamically tunable. In the quest for compactness and…
The modeling and simulation of electromagnetic wave propagation is often accompanied by a restriction to bounded domains which requires the introduction of artificial boundaries. The corresponding boundary conditions should be chosen in…
Thin structured surfaces allow flexible control over propagation of electromagnetic waves. Focusing and polarization state analysis are among functions, required for effective manipulation of radiation. Here a polarization sensitive Fresnel…
In terahertz (THz) photonics, there is an ongoing effort to develop thin, compact devices such as dielectric photonic crystal (PhC) slabs with desirable light matter interactions. However, previous works in THz PhC slabs are limited to…
We show that the finite-difference frequency-domain method is well-suited to study subwavelength lensing effects in left-handed materials (LHM's) and related problems. The method is efficient and works in the frequency domain, eliminating…
Electrical control of amplitude and phase of terahertz radiation (THz) is the key technological challenge for high resolution and noninvasive THz imaging. The lack of an active materials and devices hinders the realization of these imaging…