A5102993545- Metamaterials and Metasurfaces Applications
- Advanced Antenna and Metasurface Technologies
- Marine and fisheries research
- Coral and Marine Ecosystems Studies
- Antenna Design and Analysis
- Microwave Imaging and Scattering Analysis
- Fish Ecology and Management Studies
- Vehicle emissions and performance
- Hydrology and Sediment Transport Processes
- Hydraulic flow and structures
- Advanced Combustion Engine Technologies
- Hydrology and Watershed Management Studies
- Optical Coatings and Gratings
- Advanced Semiconductor Detectors and Materials
- Millimeter-Wave Propagation and Modeling
- Semiconductor Lasers and Optical Devices
- Impact of Light on Environment and Health
- Radiation Detection and Scintillator Technologies
- Advanced optical system design
- Healthcare Policy and Management
- Photonic Crystals and Applications
- Terahertz technology and applications
- Acoustic Wave Phenomena Research
- Tourism, Volunteerism, and Development
- Photonic Crystal and Fiber Optics
Karlsruhe Institute of Technology
2021
Florida Fish and Wildlife Conservation Commission
2018-2020
North Carolina Exploring Cultural Heritage Online
2015
Bellevue Hospital Center
2015
Duke University
2010-2014
Plasmonics (United States)
2011-2014
MetaMateria (United States)
2013
Marathon Oil (United States)
2009
Florida Department of Environmental Protection
2002
University of Warwick
2002
By leveraging metamaterials and compressive imaging, a low-profile aperture capable of microwave imaging without lenses, moving parts, or phase shifters is demonstrated. This designer allows image compression to be performed on the physical hardware layer rather than in postprocessing stage, thus averting detector, storage, transmission costs associated with full diffraction-limited sampling scene. A guided-wave metamaterial used perform reconstruction at 10 frames per second two-dimensional...
We introduce the concept of a metamaterial aperture, in which an underlying reference mode interacts with designed surface to produce series complex field patterns. The resonant frequencies elements are randomly distributed over large bandwidth (18-26 GHz), such that aperture produces rapidly varying sequence patterns as function input frequency. As frequency operation is scanned, different subsets become active, turn at scene. Scene information can thus be indexed by frequency, overall...
We demonstrate a microwave imaging system that combines advances in metamaterial aperture design with emerging computational techniques. The flexibility inherent to guided-wave, complementary metamaterials enables the of planar antenna illuminates scene dramatically varying radiation patterns as function frequency. As frequency is swept over K-band (17.5–26.5 GHz), sequence pseudorandom interrogates scene. Measurements return signal versus are then acquired and reconstructed using methods....
We present the design of a tunable metamaterial element that can serve as building block for dynamically reconfigurable aperture. The element-a complimentary electric-LC (cELC) resonator-is patterned into upper conductor microstrip transmission line, providing both means exciting radiating well independent access biasing circuitry. PIN diodes are connected across capacitive gaps cELC, and dc bias current is used to switch junction between conducting insulating states. leakage RF signal...
Employing artificially structured metamaterials provides a means of circumventing the limits conventional optical materials. Here, we use transformation optics (TO) combined with nanolithography to produce planar Luneburg lens flat focal surface that operates at telecommunication wavelengths. Whereas previous infrared TO devices have been transformations free-space, here implement an existing element create new device same characteristics but user-defined geometry.
Multiwavelength adaptive optic systems can experience phase errors when corrections measured at one wavelength are applied to others. Such originate from several sources, but poor optical coating design play a major role since the dependence of any varies greatly with wavelength, angle, and thickness. To address these errors, multilayer is proposed where effective electric field penetration depth into similar all wavelengths. Using this method, two designed for 1070 nm 1550 compared standard...
Multiwavelength adaptive optic systems can experience phase errors when corrections measured at one wavelength are applied to others. Such originate from several sources, but poor optical coating design play a major role since the dependence of any varies greatly with wavelength, angle, and thickness. To address these errors, multilayer is proposed where effective electric field penetration depth into similar all wavelengths. Using this method, two designed for 1070 nm 1550 compared standard...
We propose a general methodology and set of practical recipes for the construction ultra-broadband acoustic cloaks—structures that can render themselves concealed object undetectable by means scattering. The cloaks presented here are designed function analogously to electromagnetic cloaks. However, in fluid medium do not suffer bandwidth limitations imposed on their counterparts finite speed light vacuum. In absence specific metamaterials having arbitrary combinations quasi-static sound mass...
Abstract Shallow, hard‐bottom habitat constitutes approximately 30% of the coastal waters south Florida, United States, yet it is a chronically understudied feature marine seascape in this region. In study, we characterised general biogeographic and structural features shallow benthic communities Florida Keys, related those to abundance juvenile Caribbean spiny lobster (Panulirus argus), target one Florida's most economically valuable fisheries. We used rapid assessment techniques survey...
The Luneburg lens is a powerful imaging device, exhibiting aberration free focusing for parallel rays incident from any direction. However, its advantages are offset by focal surface that spherical and thus difficult to integrate with standard planar detector emitter arrays. Using the recently developed technique of transformation optics, it possible transform curved flat plane while maintaining perfect behavior over wide field view. Here we apply these techniques lesser-known refractive...
A metamaterial aperture operating as a leaky waveguide with resonating irises can sweep its operation frequency to modify complex field pattern no moving parts. By randomly distributing the metamaterials' resonance frequencies, we show generate random illumination patterns well suited for compressive sensing. In this way utilizes physical layer avoid redundant measurements in image reconstruction process.
We used acoustic telemetry to quantify permit Trachinotus falcatus habitat use and connectivity in proximity the Florida Keys, USA, assessed these patterns relative current fisheries management practices. From March 2017 June 2018, 45 tagged within 16 km of lower Keys were detected at stationary receivers throughout south region, majority which remained Special Permit Zone, where more extensive harvest regulations are implemented. There was a high level between nearshore flats (i.e., <3 m...
An uncooled detector has reached the thermodynamic temperature fluctuation limit, such that 98% of its total noise consisted phonon and photon fluctuations body. The device performed with a detectivity 3.8×10 9 cmHz/W, which is highest reported for any room operating in long-wave infrared ( λ ∼8−12µm). shown noise-equivalent difference 4.5 mK time constant 7.4 ms. contains subwavelength perforated absorber an absorption-per-unit-thermal mass-per-area 1.54×10 22 kg −1 m −2 , approximately...
We consider the design and implementation of a two-dimensional metamaterial relay lens, conceptually formed by flattening Maxwell fisheye lens—a perfect imaging device—through use coordinate transformation. Because Maxwell's equations are form-invariant under transformations, specifications for constitutive parameters device obtained immediately in procedure that has now become known as transformation optics. To obtain more favorable we seek quasi-conformal optics minimizes required...
The solutions to the Rotman lens design equations constrain minimum size of device. Here we use Transformation Optics compress a transmission line based by 27 percent along optical axis while maintaining beam steering range, gain and side lobe amplitudes over full frequency range original lens. transformation applied requires an anisotropic magnetic response, which is achieved in context using complementary electric dipole structures patterned into top conductor non-resonant metamaterial...
For many applications in gradient index devices and photonic crystals, it is necessary to be able design semicrystalline distributions of particles where the lattice constant distribution an arbitrary function position. We propose a method generate such which physically motivated by system interacting particles, apply implementation microwave lens. While demonstration was preformed at wavelengths, this technique would also particularly useful for designing operation IR visible wavelengths...
Imaging in long wavelength regimes holds huge potential many fields, from security to skin cancer detection. However, it is often difficult image at these frequencies – the so called 'THz gap<sup>1</sup>' no exception. Current techniques generally involve mechanically raster scanning a single detector gain spatial information<sup>2</sup>, or utilization of THz focal plane array (FPA)<sup>3</sup>. results slow acquisition times and FPAs are relatively insensitive radiation, requiring use high...