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| Isotropic Bulk Negative Index Metamaterials
Abstract: The simultaneously negative effective magnetic permeability and electric permittivity of metamaterials gives rise to exotic electromagnetic phenomena not known to exist naturally. These materials can enable, for example, ultrahigh-resolution imaging and lithography systems. Bulk isotropic three-dimensional (3D) negative index metamaterial (NIM) designs with low absorption and high transmission that operate at terahertz and optical frequencies are needed to explore all potential applications of NIMs. Direct laser writing is a promising technique for the fabrication of truly 3D large-scale photonic metamaterials. In this project we develop feasible NIM designs for DLW processes.
Keywords: Metamaterials
Collaborators: Costas Soukoulis (Ames Laboratory), Thomas Koschny (Ames Laboratory), Martin Wegener (University of Karlsruhe, Germany), Eric Mazur (Harvard University), Maria Kafesaki (University of Crete, Grece)
Support: NSF, ONR (current); DOE, USAFOSR, DARPA, ONR, FET (past)
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| Losses in Metamaterials
Abstract: In this project we explore the physical mechanisms of losses in metamaterials, develop new circumventing strategies and turn them into manufacturable designs. We study all frequency regions ranging from GHz to THz and visible. Reducing the losses, especially, in optical frequencies is critical to many exotic applications expected from metamaterials technology, such as ultra-high resolution imaging and electromagnetic invisibility cloaks.
Keywords: Metamaterials
Collaborators: Costas Soukoulis (Ames Laboratory), Thomas Koschny (Ames Laboratory), Philip Evans (Oak Ridge National Laboratory), Sahin Kaya Ozdemir (Washington University, St. Louis), and Lan Yang (Washington University, St. Louis)
Support: NSF, ONR (current); DOE, USAFOSR, DARPA, ONR, FET, ORAU, and ORNL (past)
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| Surface Plasmon Driven Negative Index Metamaterials
Abstract: In this project we investigate the interaction of Surface Plasmon Polariton (SPP) and Localized Surface Plasmon (LSP) and develop strategies to develop low-loss metamaterials that can operate at optical frequencies. Prelimanary studies show that the interaction of the SPPs of a thin metal film and LSPs of nearby periodic nano-structures can be utilized to realize negative index metamaterials in the visible spectrum.
Keywords: Metamaterials
Collaborators: Costas Soukoulis (Ames Laboratory), Thomas Koschny (Ames Laboratory), Philip Evans (Oak Ridge National Laboratory)
Support: NSF, ONR (current); DOE, AFOSR, ORAU, and ORNL (past)
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| Improving Solar Energy Conversion Efficiency with Plasmonic Nanostructures
Abstract: In this project we explore how plasmonic nanostructures can be used to improve the solar light conversion efficiency.
Keywords: Plasmonics, Metamaterials, Photovoltaics
Collaborators: Joshua Pearce (MTU), Paul Bergstrom (MTU), Anand Kulkarni (MTU), Michael Heben (University of Toledo)
Support: NSF, ThinSilicon (current); NSA, ARDA, ARO, NSF (past)
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| Diffraction-Unlimited Imaging Using Metamaterials
Abstract: In this project, we develop a super-lens that could lead to high-resolution, low-cost imaging tools becoming as commonplace as smartphones and tablet computers. Medical testing, experimental research, and many other scientific areas could become more accessible to the general public if this type of technology becomes a reality.
Keywords: Plasmonics, Metamaterials, Imaging
Collaborators: Philip Evans (Oak Ridge National Laboratory), Sahin Kaya Ozdemir (Washington University, St. Louis), and Lan Yang (Washington University, St. Louis)
Support: NSF, ONR, Superior Ideas
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| Scalable Architectures for Photonic Quantum Computers and Networks
Abstract: Despite promising developments in theory, progress in the physical realization of quantum circuits, algorithms, and communication systems has been extremely challenging to date. There are many approaches for quantum information processing. Major model physical systems include nuclear magnetic resonance, ion trap, neutral atom, cavity QED, solid state, superconducting, and optical approaches. All of these have their own advantages, but unfortunately, also their own drawbacks. Ideally, one would merge the most attractive features of these different approaches in a single technology. We explore photonic crystals, planar lightwave integrated circuits, and metamaterials as the bases for large-scale, robust and compact quantum circuit boards and processors of the next generation computers and networking devices. In this project cavity QED, solid state, and optical approaches are our main emphasises to be improved through this technology.
Keywords: Metamaterials, Plasmonics, Photonic Crystals, Planar Lightwave Circuits, Integrated Optics, Quantum Computation, Quantum Communications
Collaborators: David A. Meyer (UC San Diego), Sahin Kaya Ozdemir (Washington University, St. Louis), Lan Yang (Washington University, St. Louis), Mark Tame (University of KwaZulu-Natal, South Africa), Martin Wegener (Karlsruhe Institute of Technology, Germany), Nobuyuki Imoto (Osaka University, Japan), and Takashi Yamamoto (Japan)
Support: NSF, NRF (current); NSA, ARDA, ARO (past)
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| Metamaterial Antennas
Abstract: In this project we study metamaterials to improve conventional antennas in terms of their size, directionality, efficiency, and bandwidth.
Keywords: Metamaterials, Antennas
Collaborators: Fernando L. Teixeira (Ohio State University) and Hayrettin Odabasi (Duke University)
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| Metamaterial Spacers
Abstract: In this project, we investigate metaspacers as replacement to conventional materials to extend the capabilities of the devices produced by microfabrication. We seek answer to the question, "Can we make new materials (i.e., meta-metamaterials) with novel physical properties using metamaterials made from natural materials?"
Keywords: Metamaterials
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| Klein Paradox
Abstract: Quantum simulations is one of the main applications proposed for quantum computers. Direct simulations of, for example, an n-qubit system requires an exponential amount of space in the memory of a classical computer, which renders determining the dynamical evolution of the system intractable. Programmable 'analog' quantum computer, however, could simulate the behavior of any quantum system on demand. In this project we, particularly, explore the Klein paradox and related problems in QED and propose metamaterials as a means to simulate such systems.
Keywords: Klein Paradox, Metamaterials, Quantum Simulations
Collaborators: David A. Meyer (UC San Diego)
Support: NSA, ARDA, ARO (past)
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| Wide Band Gap Phononic Crystals
Abstract: Controlling the flow of phonons can lead to many interesting applications and basic scientific dscoveries. Integrated management of acoustic, heat and electromagnetic waves may have significant impact on novel devices employing phonon-photon interactions. Some of the potential applications include thermal management, compact wireless and sensing devices and phasers. In this project we design, fabricate and test phononic bandgap structures. We employ Brillouin light scattering in our measurements typically at GHz phononic ranges.
Keywords: Phononic Crystals
Collaborators: Zhandos Utegulov (Idaho National Laboratory), Maria Kafesaki (University of Crete, Greece), Eleftherios N. Economou (University of Crete, Greece), Costas Soukoulis (Ames Laboratory), Thomas Koschny (Ames Laboratory), Tansel Karabacak (University of Arkansas, Little Rock).
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| Long Distance High Data-Rate Quantum Key Distribution
Abstract: Photonic crystal fibers (PCFs) are attractive for the implementation of long-distance high data-rate quantum key distribution. In this project we experimentally explore the cabability of PCF technology for the next generation quantum communication and cryptography applications.
Keywords: Photonic Crystal Fibers, Quantum Cryptography
Collaborators: David A. Meyer (UC San Diego), Paul G. Kwiat (University of Illinois Urbana-Champaign), Onur Hosten (University of Illinois Urbana-Champaign), Sahin Kaya Ozdemir (Osaka University, Japan), Rasim Dermez (Kocatepe University, Turkey)
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| Photonic Crystal Fibers for High-Performance LIDAR Applications
Abstract: We explore photonic crystal fibers (PCF) to develop new enabling systems for high-performance LIDAR. Development of new fiber technologies with high-power scalability is crucial for making efficient, compact and robust light sources practical for a wide variety of LIDAR applications including environmental, scientific, and military. Given, especially the current atmospheric and geological trends in our planet, more accurate and high-precision monitoring and detection of our environment has become rather significant. PCF based lasers and amplifiers are highly attractive in the sense that they can offer solutions superior to traditional fiber technologies. They have already produced an immense literature in a very short time, ranging from hollow-core fibers to supercontinuum generation, frequency comb, spectroscopy and fiber amplifiers, among others.
Keywords: Photonic Crystal Fibers, LIDAR
Collaborators: Nan Yu (NASA)
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| Physical Cryptography
Abstract: Physical cryptosystems base their security underlying inherently complex physical systems. They can potentially provide high levels of complementary security to existing standard cryptosystems, which are in principle vulnerable against new hardware or algorithms due to their unproven mathematical assumptions and loopholes. Physical cryptography can also have advantages over quantum cryptography (special kind of physical cryptography that exploits quantum states), which demands highly sophisticated techniques to distribute the fragile quantum states. However, although many physical cryptosystems have been proposed, the search for quantifiable security and simultaneously practical implementation still continues. In this project we study how to evaluate the performance and security of these new cryptography schemes. In particular, we search for reliable and quantifiable security analysis techniques to assess those systems.
Keywords: Cryptography
Collaborators: Sadik Esener (UC San Diego)
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| Microelectromechanical Systems
Abstract: In this project we aim to work on the design and fabrication of various MEMS devices. As a part of our project we, in particular, investigated a micromachined-gas sensor. The reliability of the membrane structure for micromachined-gas sensors is one of the main concerns in MEMS technology. The major source of this problem is the stress on the membrane. We found that the use of SiO2/Si3N4/SiO2 stacked layers with optimized dimensions reduces the stress on the membrane, and hence improves the reliability. We also use electro-thermal simulations with finite element analysis (FEA) to model the structural properties of the membrane in order to reduce the stress. The appropriate selection of materials and dimensions yields maximum active area temperature of 530 degrees Celcius at the center of the membrane with a polysilicon heater element, less than 5 V supply voltage, 40 mW of power consumption, membrane edge temperature of 177 degrees Celcius and acceptable mechanical stress of 0.097 GPa. Upon realizing the structure with the modeled parameters, micromachined-gas sensors could respond to many industry/environment application demands.
Keywords: Microelectromechanical Sytems, Gas Sensors
Collaborators: Yasar Gurbuz (Sabanci University, Turkey), Ayhan Bozkurt (Sabanci University)
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| Thermal Imaging
Abstract: In this project we develop high resolution thermal imaging systems. As a part of our work we have designed a two-dimensional (2D) photonic band gap (PBG) structure for the temperature mapping of ultra-small structures, such as microelectromechanical systems (MEMS). The operational principle of the device is based on guiding and selecting the specifically tuned wavelengths through the corresponding cavities. We have shown that having processed the intensities, obtained from each cavity, in accordance with the blackbody radiation characteristics and the transmission properties of the structure, the temperature reading of the target in concern can be obtained. Despite many studies concerning guided modes in 2D PBG materials, few such sensor applications are proposed.
Keywords: Thermal Imaging, Photonic Crystals
Collaborators: Naci Inci (Bosphorus University)
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| Grand Unified Theory from the Perspectives of Heat Transfer and Fluid Mechanics
Abstract: It was shown by Alaettin Yildiz [A. Yildiz, Dissertation D83, Technical University of Berlin, Germany (1965)] experimentally in mid 1960s that there exists previously unknown critical value for the rotation rate of a cylinder above which occurs a sharp transition in the quantitative dependence of heat transfer on the system parameters. He considered a rotating cylinder that was subjected to an airstream along the axis of rotation. His objective was to characterize the measured aerodynamic heat transfer in terms of the dimensionless numbers describing the system. The convective heat transfer was closely related to the characteristics of the flow around the vicinity of the cylinder surface. In this project we explore the possibility of similar phenomena in the early stages of Big Bang.
Keywords: Fluid Dynamics, Grand Unified Theory, Heat Transfer
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