Related papers: Ultra-broadband Terahertz Perfect Absorber Based o…
This work theoretically analyzes the sound absorption properties of a chirped multi-layer porous material including transmission, in particular showing the broadband unidirectional absorption properties of the system. Using the combination…
The terahertz spectra of the dynamic conductivity and radiation absorption coefficient in germanium-silicon heterostructures with arrays of Ge hut clusters (quantum dots) have been measured for the first time in the frequency range of…
Black phosphorus (BP), a relative new plasmonic two-dimensional (2D) material, offers unique photonic and electronic properties. In this work, we propose a new tunable and broadband ultrathin coherent perfect absorber (CPA) device operating…
Near perfect infrared light absorption at multi-spectral wavelengths has been experimentally demonstrated by using multiplexed metal square plasmon resonance structures. Optical power absorption over 95% has been observed in dual-band…
The plane wave scattering and absorption by finite and infinite gratings of free-space standing infinitely long graphene strips are studied in the THz range. A novel numerical approach, based on graphene surface impedance, hyper-singular…
We present experimental demonstration of electronically tunable metamaterial perfect absorbers in the terahertz regime. By incorporation of active liquid crystal into strategic locations within the metamaterial unit cell we are able to…
Compact devices for broadband polarization control in the terahertz (THz) regime are challenging due to the intrinsic phase dispersion of birefringent materials and resonant structures. Here, we demonstrate high-performance broadband THz…
The relation between free carrier absorption and intersubband transitions in semiconductor heterostructures is resolved by comparing a sequence of structures. Our numerical and analytical results show how free carrier absorption evolves…
Tunable bandpass terahertz filters are demanded in various key applications such as hyperspectral imagers, miniaturized spectrometers, and high-speed wireless communication systems. Here, a mechanically reconfigurable double-layered…
We propose to use logarithmic spiral resonators for efficient absorption of microwaves. By combining their scale invariant geometries and Fabry-Perot-type resonances stemming from the fundamental TM mode, we realize a microwave metasurface…
This work presents a new design for broadband absorption of low-frequency acoustic waves using a thin coating made of subwavelength acoustic resonators arranged periodically on a reflective surface. We first study the associated scattering…
Modern nanophotonic and meta-optical devices utilize a tremendous number of structural degrees of freedom to enhance light--matter interactions. A fundamental question is how large such enhancements can be. We develop an analytical…
In this work, a metamaterial selective solar absorber made of nanostructured titanium gratings deposited on an ultrathin MgF2 spacer and a tungsten ground film is proposed and experimentally demonstrated. Normal absorptance of the…
In the millimeter wave (30-300 GHz) and Terahertz (0.1-10 THz) frequency bands, high spreading loss and molecular absorption often limit the signal transmission distance and coverage range. In this paper, four directions to tackle the…
We demonstrate that a self-complementary checkerboard-like metasurface works as a broadband coherent perfect absorber (CPA) when symmetrically illuminated by two counter-propagating incident waves. A theoretical analysis based on wave…
We study the optimal diffusive transmission and absorption of broadband or polychromatic light in a disordered medium. By introducing matrices describing broadband transmission and reflection, we formulate an extremal eigenvalue problem…
Utilizing solar energy requires perfect absorption by photovoltaic cells for efficient conversion of solar energy into useful electrical energy. Metasurfaces can, not only be used to absorb solar energy efficiently but, they do so with…
We present an ultra broadband thin-film infrared absorber made of saw-toothed anisotropic metamaterial. Absorbtivity of higher than 95% at normal incidence is supported in a wide range of frequencies, where the full absorption width at half…
We propose using THz frequency selective surfaces interrogated with THz subwavelength optical fibers as sensors for monitoring of the optical properties of thick films that are brought in contact with such surfaces. Changes in the test film…
Narrowband perfect absorbers are interesting for spectrum sensing, molecular detection, and infrared imaging. However, their design remains constrained by intuitive, iterative methods that lack flexibility, while also facing challenges in…