Related papers: Anti-reflection coating design for metallic terahe…
In this paper, we propose a new approach for realizing antireflection coating using metamaterials. In this approach, a subwavelength array of metallic pillars (with square cross-section) is used for implementing antireflection coating. The…
We present a novel antireflection approach utilizing planar metamaterials on dielectric surfaces. It consists of a split-ring resonator array and a metal mesh separated by a thin dielectric spacer. The coating dramatically reduces the…
Wireless communications in the terahertz band (0.1-10 THz) is a promising and key wireless technology enabling ultra-high data rate communication over multi-gigahertz-wide bandwidths, thus fulfilling the demand for denser networks. The…
A metamaterial structure consisting of a one-dimensional metal/air-gap subwavelength grating is investigated for optical antireflection coating on germanium substrate in the infrared regime. For incident light polarized perpendicularly to…
We demonstrate results of a simulation of nonlinear reflection of intensive terahertz radiation from a silicon-on-metal metasurface involving an excitation of a high-Q trapped mode resonance. Conditions are presented to observe effects of…
Antireflection coatings are ubiquitous in optical systems, where they maximize transmission and suppress undesirable reflections by impedance-matching uniform interfaces. Extending this principle to metasurfaces, however, is fundamentally…
Broadband refractive optics realized from high index materials provide compelling design solutions for the next generation of observatories for the Cosmic Microwave Background (CMB), and for sub-millimeter astronomy. In this paper, work is…
We have developed and tested an antireflection (AR) coating method for silicon lenses at cryogenic temperatures and millimeter wavelengths. Our particular application is a measurement of the cosmic microwave background. The coating consists…
We present a metamaterial-based terahertz (THz) sensor for thickness measurements of subwavelength-thin materials and refractometry of liquids and liquid mixtures. The sensor operates in reflection geometry and exploits the frequency shift…
Although high-resistivity, low-loss silicon is an excellent material for THz transmission optics, its high refractive index necessitates antireflection treatment. We fabricated a wide-bandwidth, two-layer antireflection treatment by cutting…
We describe a novel artificial dielectric material which has applications at millimetre and submillimetre wavelengths. The material is manufactured from layers of metal mesh patterned onto thin polypropylene sheets which are then bonded…
The increasing scale of cryogenic detector arrays for sub-millimeter and millimeter wavelength astrophysics has led to the need for large aperture, high index of refraction, low loss, cryogenic refracting optics. Silicon with n = 3.4, low…
Reflectarrays composed of resonant microstrip gold patches on a dielectric substrate are demonstrated for operation at terahertz frequencies. Based on the relation between the patch size and the reflection phase, a progressive phase…
Refractive optical elements are widely used in millimeter and sub-millimeter astronomical telescopes. High resistivity silicon is an excellent material for dielectric lenses given its low loss-tangent, high thermal conductivity and high…
We report on design and fabrication of nano-composite metal-dielectric thin film coatings with high reflectance asymmetries. Applying basic dispersion engineering principles to model a broadband and large reflectance asymmetry, we obtain a…
All-dielectric nanostructures have recently emerged as a promising alternative to plasmonic devices, as they also possess pronounced electric and magnetic resonances and allow effective light manipulation. In this work, we study optical…
We developed a broadband two-layer anti-reflection (AR) coating for use on a sapphire half-wave plate (HWP) and an alumina infrared (IR) filter for the cosmic microwave background (CMB) polarimetry. Measuring the faint CMB B-mode signals…
Planar metamaterials have been recently proposed for thin dielectric film sensing in the terahertz frequency range. Although the thickness of the dielectric film can be very small compared with the wavelength, the required area of sensed…
We present a metamaterial that acts as a strongly resonant absorber at terahertz frequencies. Our design consists of a bilayer unit cell which allows for maximization of the absorption through independent tuning of the electrical…
We report on the first use of laser ablation to make sub-millimeter, broad-band, anti-reflection coatings (ARC) based on sub-wavelength structures (SWS) on alumina and sapphire. We used a 515 nm laser to produce pyramid-shaped structures…