Massachusetts Institute of Technology

Boston University

Los Alamos National Security, LLC

Schlumberger Technology Corporation

US Government As Represented by the Secretary of the Army

Sandia Corporation

Tufts University

The Trustees of Boston College

Richard Douglas Averitt

Kebin Fan

Keith Adam Nelson

Xin Zhang

Harold Young Hwang

Willie John Padilla

Andrew Strikwerda

John F O'Hara

Mengkun Liu

Aaron Sternbach

Hu Tao

Fiorenzo G Omenetto

John Dalton Williams

David L Kaplan

Michael M Herron

Ronald E G Van Hal

Michael Wraback

Igal Brener

Andrew Speck

Eric A Shaner

A Ballard Andrews

Mark Lee

Konstantinos Tsioris

Grace D Metcalfe

Hou-Tong Chen

Abul Kalam Azad

Logan Chieffo

Xomalin Guaiuli Peralta

Evgenya Smirnova

Houtong Chen

An apparatus for detecting electromagnetic radiation within a target frequency range is provided. The apparatus includes a substrate and one or more resonator structures disposed on the substrate. The substrate can be a dielectric or semiconductor material. Each of the one or more resonator structures has at least one dimension that is less than the wavelength of target electromagnetic radiation within the target frequency range, and each of the resonator structures includes at least two conductive structures separated by a spacing. Charge carriers are induced in the substrate near the spacing when the resonator structures are exposed to the target electromagnetic radiation. A measure of the change in conductivity of the substrate due to the induced charge carriers provides an indication of the presence of the target electromagnetic radiation.

Detection of electromagnetic radiation using nonlinear materials

The invention relates to silk electronic components and methods for fabricating the same. The silk electronic components can be used as novel devices, such as implantable bioelectric and/or biophotonic devices, biosensors, surveillance devices, invisible cloaks, electromagnetic concentrators or antennas.

Silk electronic components

A reflection-mode waveplate for operation in the terahertz region by shifting the phase between two perpendicular polarization components of the light wave, comprising a ground plane; an array of polygonal unit cells; the polygonal unit cells comprising a polymer positioned between the ground plane and the exterior of the array of polygonal patches.

Electromagnetic composite-based reflecting terahertz waveplate

A method of analyzing physical properties of a sample includes obtaining the sample and obtaining an electromagnetic spectrum of the sample using terahertz spectroscopy. A sample complex permittivity is computed from the electromagnetic spectrum of the sample. The method further includes estimating the constituents and the constituent fractions and computing an estimated effective complex permittivity based upon a model and the constituent fractions. The method further includes comparing the computed sample complex permittivity with the estimated effective complex permittivity in order to determine the physical properties the sample.

System and method of determining rock properties using terahertz-band dielectric measurements

A geometrically modifiable resonator is comprised of a resonator disposed on a substrate, and a means for geometrically modifying the resonator. The geometrically modifiable resonator can achieve active optical and/or electronic control of the frequency response in metamaterials and/or frequency selective surfaces, potentially with sub-picosecond response times. Additionally, the methods taught here can be applied to discrete geometrically modifiable circuit components such as inductors and capacitors. Principally, controlled conductivity regions, using either reversible photodoping or voltage induced depletion activation, are used to modify the geometries of circuit components, thus allowing frequency tuning of resonators without otherwise affecting the bulk substrate electrical properties. The concept is valid over any frequency range in which metamaterials are designed to operate.

Dynamic frequency tuning of electric and magnetic metamaterial response

Terahertz metamaterials comprise a periodic array of resonator elements disposed on a dielectric substrate or thin membrane, wherein the resonator elements have a structure that provides a tunable magnetic permeability or a tunable electric permittivity for incident electromagnetic radiation at a frequency greater than about 100 GHz and the periodic array has a lattice constant that is smaller than the wavelength of the incident electromagnetic radiation. Microfabricated metamaterials exhibit lower losses and can be assembled into three-dimensional structures that enable full coupling of incident electromagnetic terahertz radiation in two or three orthogonal directions. Furthermore, polarization sensitive and insensitive metamaterials at terahertz frequencies can enable new devices and applications.

Terahertz metamaterials

An apparatus and method are disclosed for detecting terahertz radiation at room temperature. A detecting pixel includes a sub-wavelength split-ring resonator, and is mechanically coupled to (but thermally decoupled from) a substrate via a cantilever formed from two materials that have a significant mismatch in their thermal expansion coefficients. Incident radiation causes the split-ring resonator to resonate, thereby generating heat that is transferred to the cantilever, causing the cantilever to flex. An optical readout system includes a secondary light source, such as a laser, that shines on a reflective surface on the pixel, whereby a photodiode detects the reflected light and permits calculation of a relative deflection of the pixel in the nanometer range. An exemplary detector has a noise equivalent power rating of approximately 60 pW/&#x221a;Hz.

Thermal imager using metamaterials

Metamaterial structures are taught which provide for the modulation of terahertz frequency signals. Each element within an array of metamaterial (MM) elements comprises multiple loops and at least one gap. The MM elements may comprise resonators with conductive loops and insulated gaps, or the inverse in which insulated loops are present with conductive gaps; each providing useful transmissive control properties. The metamaterial elements are fabricated on a semiconducting substrate configured with a means of enhancing or depleting electrons from near the gaps of the MM elements. An on to off transmissivity ratio of about 0.5 is achieved with this approach. Embodiments are described in which the MM elements incorporated within a Quantum Cascade Laser (QCL) to provide surface emitting (SE) properties.

Active terahertz metamaterial devices

Growing community of inventors

Newton, MA, United States of America

Richard Douglas Averitt