A5064143322- Metamaterials and Metasurfaces Applications
- Thermal Radiation and Cooling Technologies
- Plasmonic and Surface Plasmon Research
- Photonic and Optical Devices
- Transition Metal Oxide Nanomaterials
- Photonic Crystals and Applications
- Orbital Angular Momentum in Optics
- Optical Coatings and Gratings
- Advanced Antenna and Metasurface Technologies
- Cold Atom Physics and Bose-Einstein Condensates
- Optical properties and cooling technologies in crystalline materials
- Calibration and Measurement Techniques
- Optical Wireless Communication Technologies
- Advanced Fiber Optic Sensors
- Gold and Silver Nanoparticles Synthesis and Applications
- Optical Polarization and Ellipsometry
- Perovskite Materials and Applications
- 2D Materials and Applications
- Advanced Thermodynamics and Statistical Mechanics
- Advanced Fiber Laser Technologies
- Spectroscopy and Laser Applications
- Chalcogenide Semiconductor Thin Films
- Crystal Structures and Properties
- Quantum optics and atomic interactions
- Gas Sensing Nanomaterials and Sensors
University of Wisconsin–Madison
2016-2025
Madison Area Technical College
2022
Harvard University
2009-2015
Singapore Institute of Manufacturing Technology
2012
Texas A&M University
2012
Harvard University Press
2012
William & Mary
2012
Williams (United States)
2012
University of Eastern Finland
2012
Cornell University
2008
Conventional optical components rely on gradual phase shifts accumulated during light propagation to shape beams. New degrees of freedom are attained by introducing abrupt changes over the scale wavelength. A two-dimensional array resonators with spatially varying response and subwavelength separation can imprint such discontinuities propagating as it traverses interface between two media. Anomalous reflection refraction phenomena observed in this regime optically thin arrays metallic...
The concept of optical phase discontinuities is applied to the design and demonstration aberration-free planar lenses axicons, comprising a phased array ultrathin subwavelength spaced antennas. axicons consist radial distributions V-shaped nanoantennas that generate respectively spherical wavefronts non-diffracting Bessel beams at telecom wavelengths. Simulations are also presented show our designs applicable high numerical aperture such as flat microscope objectives.
We demonstrate optically thin quarter-wave plates built with metasurfaces that generate high-quality circularly polarized light over a broad wavelength range for arbitrary orientation of the incident linear polarization. The metasurface consists an array plasmonic antennas spatially varying phase and polarization responses. Experimentally demonstrated high degree circular (>0.97) from λ = 5 to 12 μm, representing major advance in performance compared previously reported plasmonics-based wave plates.
Color correcting planar optics The functionality of many bulk optical elements can now be replaced by specially designed structures fabricated in thin films. This approach, however, has generally been applicable to only a narrow band wavelengths. Aieta et al. show that chromatic dispersion, or color dependence, compensated for the judicious design surface. results demonstrate general approach fabrication broadband and lightweight engineered into Science , this issue p. 1342
Dynamically reconfigurable metasurfaces open up unprecedented opportunities in applications such as high capacity communications, dynamic beam shaping, hyperspectral imaging, and adaptive optics. The realization of performance metasurface-based devices remains a great challenge due to very limited tuning ranges modulation depths. Here we show that widely tunable metasurface composed optical antennas on graphene can be incorporated into subwavelength-thick cavity create an electrically...
We show that perfect absorption can be achieved in a system comprising single lossy dielectric layer of thickness much smaller than the incident wavelength on an opaque substrate by utilizing nontrivial phase shifts at interfaces between media. This design is implemented with ultra-thin (∼λ/65) vanadium dioxide (VO2) sapphire, temperature tuned vicinity VO2 insulator-to-metal transition, leading to 99.75% λ = 11.6 μm. The structural simplicity and large tuning range (from ∼80% 0.25%...
Plasmonic antennas enable the conversion of light from free space into subwavelength volumes and vice versa, which facilitates manipulation at nanoscale. Dynamic control properties is desirable for many applications, including biochemical sensors, reconfigurable meta-surfaces compact optoelectronic devices. The combination metallic structures graphene, has gate-voltage dependent optical properties, emerging as a possible platform electrically controlled plasmonic In this paper, we...
Experiments on ultrathin anisotropic arrays of subwavelength optical antennas display out-of-plane refraction. A powerful three-dimensional (3D) extension the recently demonstrated generalized laws refraction and reflection shows that interface imparts a tangential wavevector to incident light leading anomalous beams, which in general are noncoplanar with beam. The refracted beam direction can be controlled by varying angle between plane incidence antenna array.
A flat optical device that generates vortices with a variety of topological charges is demonstrated. This spatially modulates light beams over distance much smaller than the wavelength in direction propagation by means an array V-shaped plasmonic antennas sub-wavelength separation. Optical are shown to develop after from array, feature has major potential implications for integrated optics.
Nanoscale optical resonators enable a new class of flat components called metasurfaces. This approach has been used to demonstrate functionalities such as focusing free monochromatic aberrations (i.e., spherical and coma), anomalous reflection, large circular dichroism. Recently, dielectric metasurfaces that compensate the phase dispersion responsible for chromatic have demonstrated. Here, we utilize an aperiodic array coupled nanoresonators multiwavelength achromatic lens. The focal length...
Conventional optical components rely on the propagation effect to control phase and polarization of light beams. One can instead exploit abrupt changes associated with scattered from resonators propagation. In this paper, we discuss responses anisotropic plasmonic antennas a new class planar ("metasurfaces") based arrays these antennas. To demonstrate versatility metasurfaces, show design experimental realization number flat components: 1) metasurfaces constant interfacial gradient that...
Miniaturized spectrometers have significant potential for portable applications such as consumer electronics, health care, and manufacturing. These demand low cost high spectral resolution, are best enabled by single-shot free-space-coupled that also sufficient spatial resolution. Here, we demonstrate an on-chip spectrometer can satisfy all of these requirements. Our device uses arrays photodetectors, each which has a unique responsivity with rich features. responsivities created complex...
We report a new type of holographic interface, which is able to manipulate the three fundamental properties light (phase, amplitude, and polarization) over broad wavelength range. The design strategy relies on replacing large openings conventional holograms by arrays subwavelength apertures, oriented locally select particular state polarization. resulting optical element can therefore be viewed as superposition two independent structures with very different length scales, that is, hologram...
Abstract Optical absorbers find uses in a wide array of applications across the electromagnetic spectrum, including photovoltaic and photochemical cells, photodetectors, optical filters, stealth technology, thermal light sources. Recent efforts have sought to reduce footprint absorbers, conventionally based on graded structures or Fabry‐Perot‐type cavities, by using emerging concepts plasmonics, metamaterials, metasurfaces. Unfortunately, these new absorber designs require patterning...
Active, widely tunable optical materials have enabled rapid advances in photonics and optoelectronics, especially the emerging field of meta-devices. Here, we demonstrate that spatially selective defect engineering on nanometer scale can transform phase-transition into metasurfaces. Using ion irradiation through nanometer-scale masks, selectively defect-engineered insulator-metal transition vanadium dioxide, a prototypical correlated material whose properties change dramatically depending...
We demonstrate that the resonances of infrared plasmonic antennas can be tuned or switched on/off by taking advantage thermally driven insulator-to-metal phase transition in vanadium dioxide (VO2). Y-shaped were fabricated on a 180 nm film VO2 deposited sapphire substrate, and their shown to depend temperature proximity its transition, good agreement with full-wave simulations. achieved tunability resonance wavelength approximately 10% (>1 μm at λ∼10 μm).
Thermal radiation from conventional emitters, such as the warm glow of a light bulb, increases with temperature: hotter more it glows. emitters that buck this trend could lead to many unconventional thermal devices. Researchers have engineered (meta)material by exploiting unique structural and electronic phase changes vanadium oxide at around 70${}^{\ensuremath{\circ}}$C.
Abstract The insulator‐to‐metal transition (IMT) in vanadium dioxide (VO 2 ) can enable a variety of optics applications, including switching and modulation, optical limiting, tuning resonators. Despite the widespread interest VO for optics, wavelength‐dependent properties across its IMT are scattered throughout literature, sometimes contradictory, not available at all some wavelength regions. Here, complex refractive index thin films is characterized free‐space wavelengths from 300 nm to 30...
A radiative vapor condenser sheds heat in the form of infrared radiation and cools itself to below ambient air temperature produce liquid water from vapor. This effect has been known for centuries, is exploited by some insects survive dry deserts. Humans have also using condensation dew collection. However, all existing condensers must operate during nighttime. Here, we develop daytime that continue 24 h a day. These can under direct sunlight, without active consumption energy. Combined with...
Enhancing nonlinear processes at the nanoscale is a crucial step toward development of nanophotonics and new spectroscopy techniques. Here we demonstrate novel plasmonic structure, called nanocavity grating, which shown to dramatically enhance surface optical processes. It consists resonant cavities that are periodically arranged combine local grating resonances. The four-wave mixing signal generated in our gold enhanced by factor up ≈2000, 2 orders magnitude higher than previously reported.