National Technology & Engineering Solutions of Sandia, LLC

Michael Goldflam

David W Peters

Paul Davids

Thomas Edwin Beechem, Iii

Stephen Wayne Howell

Isaac Ruiz

Michael B Sinclair

Igal Brener

Eric A Shaner

Anna Tauke-Pedretti

Jin K Kim

Salvatore Campione

Evan Michael Anderson

Clark N Kadlec

D Bruce Burckel

Aaron J Pung

An apparatus is provided for nanoantenna-enhanced detection of infrared radiation. The apparatus includes one or more detector pixels. A plurality of detector pixels can constitute a focal plane array (FPA). Each detector pixel carries at least a first and a second subpattern of nanoantenna elements, with elements of the second subpattern interpolated between elements of the first subpattern. Each detector pixel also includes separate collection electrodes for collecting photogenerated current from the respective subpatterns.

Continuous full-resolution two-color infrared detector

A monolithically integrated, tunable infrared pixel comprises a combined broadband detector and graphene-enabled tunable metasurface filter that operate as a single solid-state device with no moving parts. Functionally, tunability results from the plasmonic properties of graphene that are acutely dependent upon the carrier concentration within the infrared. Voltage induced changes in graphene's carrier concentration can be leveraged to change the metasurface filter's transmission thereby altering the 'colors' of light reaching the broadband detector and hence its spectral responsivity. The invention enables spectrally agile infrared detection with independent pixel-to-pixel spectral tunability.

Tunable infrared pixels having unpatterned graphene layer and conductive metasurface

A time-resolved microwave reflectance apparatus comprises a pulsed or modulated optical source that irradiates a semiconductor sample with an excitation pump beam, a microwave oscillator that irradiates the sample with a continuous beam of microwaves, and a microwave detector that detects the microwaves reflected by the sample. Therefore, charge detection, rather than conventional absorption measurements (that detect the loss of photons), can be used to extract the absorption coefficient and band edge of a semiconductor material.

Apparatus and method to measure semiconductor optical absorption using microwave charge sensing

Dielectric resonators provide a building block for the development of low-loss resonant metamaterials because they replace lossy ohmic currents of metallic resonators with low-loss displacement currents. The spectral locations of electric and magnetic dipole resonances of a dielectric resonator can be tuned by varying the resonator geometry so that desired scattering properties are achieved.

Optical devices enabled by vertical dielectric Mie resonators

An actively tunable optical filter can control the amplitude of reflected infrared light. The filter exploits the dependence of the excitation energy of plasmons in a continuous and unpatterned sheet of graphene, on the Fermi-level, which can be controlled by conventional electrostatic gating. An exemplary filter enables simultaneous modification of two distinct spectral bands whose positions are dictated by the device geometry and graphene plasmon dispersion. Within these bands, the reflected amplitude can be varied by over 15% and resonance positions can be shifted by over 90 cm. Electromagnetic simulations verify that tuning arises through coupling of incident light to graphene plasmons by a nanoantenna grating structure. Importantly, the tunable range is determined by a combination of graphene properties, device structure, and the surrounding dielectrics, which dictate the plasmon dispersion. Thus, the underlying design is applicable across a broad range of infrared frequencies.

Tunable graphene-based infrared reflectance filter having patterned nanoantenna layer and unpatterned graphene layer

Growing community of inventors

Albuquerque, NM, United States of America

Michael Goldflam