Robert Magnusson - US grants

During the past five years, UT Arlington's Department of Electrical Engineering has conducted an experimental program involving undergraduate scholars in research projects. This program builds on the past experience. Specifically, this current program is strengthened by increasing the funding, raising the number of students to eight, providing research opportunities during summers, and emphasizing recruitment of underrepresented US citizens and permanent residents in electrical engineering. The philosophy of the program is the integration of undergraduate scholars into existing research projects and the significant interaction between faculty and students. The scholars are encouraged to be creative and productive and are expected to gain considerable independence during two consecutive academic semesters. A full-time summer research opportunity is then available with significant research contributions possible.

The University of Texas at Arlington's Department of Electrical Engineering is conducting a Research Experiences for Undergraduates program. The program will be the participation of undergraduate scholars in research projects and the significant interaction between faculty and students. There will be an academic year component, open to all qualified scholars, and a summer component, designed to emphasize the participation of underrepresented minorities. The scholars will be expected to exhibit qualities such as creativity, productivity, effective communication, and independence upon completion of their training in the program. Students will participate in the complete research process. They will select a research topic with their faculty mentor, write a research proposal, perform a literature search, attend and participate in an Ethics Forum, conduct the research, analyze data, write progress and final reports, present the work orally, and evaluate the experience.

9512504 Maldonado This proposal requests advanced instrumentation for characterizing new optical materials (nonlinear biaxial crystals organic and inorganic ) and wave guide devices. The instrumentation (i.e. laser systems, ellipsometer, spectrum analyzer, etc..) would be used to verify experimentally the theoretical' studies and predictions of the Electro-Optics Group at the University of Texas in Austin. In particular, the propagation constants of hybrid modes in planar and channel biaxial waveguides are to examined as well as waveguide devices, such as guided-model resonance filters. ***

The university is creating a joint Electrical Engineering/Physics optics laboratory consisting of (1) the fundamentals of optics and (2) optical system design and engineering. The objective of the lab center is to educate undergraduate students in the fundamentals of optics; in interdisciplinary problem-solving; in design, analysis, and manufacturing issues; in handling and using optics in a variety of applications; and in nontechnical skills, such as written and oral communications. In the first semester, students learn fundamental optical techniques. The second semester focuses on more sophisticated procedures, such as holography, four-wave mixing, and advanced fiber optics. The class is divided into teams, and each team is assigned a design problem. Written technical reports, in professional format, are required, as are formal presentations. The lab complements an optics course sequence and is used for demonstrations to and active participation by K-12 students in optics experiments.

9973908
Maldonado

The goal of this POWRE proposal is to provide the opportunity for the PI to develop research training in organic materials and processes to compliment her work in nonlinear optical waveguides and to supervise more effectively her students from different home departments. In addition, a multidisciplinary research training program and graduate curriculum in organic nonlinear optics will be initiated through this effort. Current research involves fabricating waveguides using chromophore-doped polymers followed by electric field poling. A new effort is initiated to fabricate these waveguides by ionic self assembly. Planar waveguide structures have been grown by a modified technique developed by the PI's students. This approach will be used to design optical fiber devices for frequency conversion by creating a nonlinear cladding with ISAMs. To the knowledge of the PI, this idea has not been reported in the literature. The idea of producing a nonlinear fiber cladding rather than core has not been developed to any great extent. The PI knows of only one other attempt (in 1988) using Langmuir-Blodgett films. This project will be used as a means for the PI to develop relevant multidisciplinary research training in organic chemistry and materials science. This training will allow her to supervise her students more effectively and to develop a multidisciplinary graduate program involving Electrical Engineering, Physics, Chemistry, and Materials Science. A POWRE award would be important for revitalizing the PI's research program and extend it to new areas. The research program of the PI has been affected in recent years by significant personal events.

This Nanotechnology in Undergraduate Education (NUE) award to the University of Connecticut supports a multidisciplinary team, Professors Faquir Jain, John Ayers, R. Magnusson, and Rajeev Bansal, Department of Electrical and Computer Engineering, and F. Papadimitrakopoulos, Institute of Materials Science, and B. Sinkovic, Department of Physics, for their work to prepare Engineering and Science majors for a future role in industries impacted by nanotechnology. This will be accomplished through the following steps: (1) develop teaching modules to introduce basic nanoscience and nanotechnology (NSNT) concepts in an existing core of four lower division (Freshmen and Sophomore) courses, (2) develop teaching modules for strengthening nanostructures concepts in four existing Core Courses and four Professional Elective (PE/PR) upper division (Junior and Senior) courses, (3) create two new team-taught upper division NSNT courses, and (4) provide Senior Design experience in Nanotechnology. The teaching modules, new NSNT course material (including dedicated software), and laboratory training will be available to institutions participating in Connecticut Microelectronics and Optoelectronics Consortium (CMOC) [Trinity College, Yale University, Southern Connecticut State University, and U. Bridgeport and 18 industrial members], and also to research collaborators, Prof. W. Huang (Electrical Engineering Dept., US Military Academy, West Point, NY) and Prof. S. K. Islam (Electrical and Computer Engineering, University of Tennessee, Knoxville, TN).

The proposal for this award was received in response to the Nanoscale Science and Engineering Education (NSEE) announcement, NS 03-044, category NUE and was jointly funded by the Division of Chemical and Transport Systems (CTS), Directorate for Engineering (ENG), Division of Materials Research, the Division of Mathematical Sciences (DMS) in the Directorate for Mathematical and Physcial Sciences (MPS), and the Diectorate for Computer and Information Sciences and Engineering (CISE)

This award provides support for an REU Site at the University of Connecticut for up to three years. Eight students will be recruited for an eight-week summer experience and eight students will participate in an academic year program. Students will have a unique opportunity to engage in research related to electrical and computer engineering. The program will serve to encourage undergraduates to pursue advanced degrees in engineering and thus impact the nations need to increase the number of U.S. citizens and permanent residents engaged in research-related careers. It is also anticipated that this REU Site will have a Broader Impact on the nations need to have broader participation in the research enterprise of citizens and permanent residents from demographic groups traditionally underrepresented in science and engineering.

0524383
Magnusson

The goal of this project is to conduct analytical, numerical, and experimental research on the resonant leaky modes associated with periodic refractive-index lattices such as gratings and photonic crystals. As shown by numerous simulations, single-layer subwavelength periodic leaky-mode waveguide films with binary profiles can be applied to fashion optical elements that provide a remarkably broad variety of tailored spectral characteristics. These sparse elements with one-dimensional periodicity can function as new types of narrow-line bandpass filters, polarized wideband reflectors, polarizers, polarization-independent elements, and as wideband antireflectors. The project addresses fabrication and characterization of new device concepts based on these structures with the main objectives as follows:
1. Develop an analytical model for resonance elements with weakly modulated asymmetric profiles to elucidate the detailed resonance physics and leaky-mode interactions in this limit.
2. Numerically quantify spectral enhancements realized by addition of homogeneous layers.
3. Numerically characterize the resonant leaky-mode photonic band structure.
4. Numerically quantify resonant leaky-mode spatial field distributions to clarify the leaky-mode interaction dynamics.
5. Fabricate and test resonant elements using silicon-on-insulator wafers.

Intellectual merit: This project provides new, creative directions in photonic device research by addressing fundamental phenomena for subwavelength leaky-mode resonant device technologies. The preliminary results indicate that a new class of optical elements is possible and explain how pertinent devices might be implemented. The associated physical properties are explained in terms of the photonic band structure and its relation to the structural symmetry of the elements. The interaction dynamics of the leaky modes at resonance contribute to sculpting the diverse spectral bands observed by numerical simulations. The leaky-mode spectral placement, their spectral density, and their levels of interaction are shown to be fundamentally important in understanding device operation. These ideas merit further theoretical and experimental research and development as proposed.

Broader impacts: Single-layer leaky-mode elements can have functionality somewhat comparable to multilayer homogeneous thin-film elements. Traditional thin optical films are applied to design and fabricate elements with diverse spectral features which are widely used in optical systems. The guided-mode resonance elements of interest in this proposal possess analogous spectral versatility but are governed by different physics. Thus, new possibilities in function and applications can be envisioned that may provide complementary capability with the field of thin-film optics. Finally, the project will benefit graduate and undergraduate education and enhance the experience of numerous high school students and teachers attending summer programs in engineering.

Intellectual Merit:
The objective of this project is to conduct theoretical and experimental research on tunable nanostructured resonance elements. The project is motivated by recent theoretical results that demonstrate substantial spectral tunability with minimal mechanical movement. The proposed nano/micro-electromechanically tunable pixels rely on leaky-mode resonance effects in subwavelength photonic lattices that constitute periodic waveguides. It is of interest to explore the utility of this concept across the wavelength range from ~0.4 m to ~2 m by numerical simulations and fabrication of prototype elements. A comprehensive plan of research to address numerous interesting facets of this device class is proposed. The project is intellectually meritorious in that new, original directions in photonic device design based on nanostructured subwavelength elements will be pursued. The study of coexisting plasmonic and leaky-mode resonance effects is of fundamental scientific interest. We expect the project to establish a new class of tunable optical elements and to aid device design and fabrication.

Broader Impact:
If the research verifies the practicality of these concepts, this work can have a significant impact in promoting new device technology. Applications such as tunable filters, variable reflectors, modulators, and tunable pixels appear feasible. These devices may be useful as pixels in new, planar, ultra thin spatial light modulators for display applications as well as in other systems including tunable multispectral detectors, multispectral analysis systems, polarization discrimination and analysis systems, and tunable lasers. In addition, this project supports development of research capability and education in photonic nanostructures at the University of Connecticut providing analytical and experimental experience for graduate and undergraduate students. The results of this research will be disseminated in journals and conferences. Because there is strong global emphasis on the study of periodic layers and lattices, our publications and results, illustrating the interesting effects and applications realized in the leaky-mode regime and in the mixed plasmonic/leaky-mode regime, might stimulate additional research and development.

Project objective: The objective of this project is to conduct theoretical and experimental research on the dispersion properties of nanostructured resonance elements. Fundamentally new types of dispersive devices using leaky-mode resonance effects in subwavelength photonic lattices will be designed, fabricated, and tested.

Intellectual merit: This project charts new directions in photonic device technology based on nanostructured subwavelength elements. The proposed devices are unexploited in slow-light engineering. This project will define their applicability. Computations show that leaky-mode resonance devices compare favorably with leading concepts in the field. Although based on totally different fundamentals, in structure and device density, the proposed concept is similar to photonic-crystal based micro-resonator chips whose fabrication is particularly challenging. It appears that the proposed leaky-mode resonance delay lines can be fabricated more directly. Additionally, the elements show flat transmission spectra across useful bands. Detailed comparison requires fabrication and testing of prototype devices. As very little is currently known about these effects in the context of slow light, this project constitutes basic research.

Broader impact: If the research verifies the practicality of these concepts, this work can have a major impact in promoting new device technology. Very compact optical delay lines, signal buffers in all-optical communication systems, and light-storage elements would become feasible. Moreover, this project is aligned with a broad plan to develop research and education in photonic nanostructures at the University of Texas at Arlington. It will strengthen research in photonic crystals and integrated photonic circuits and support efforts in building nanofabrication methods and infrastructure. With the principal investigator?s recent appointment to the Texas Instruments Distinguished University Chair in Nanoelectronics, major funding for equipment and facilities was provided. This project, which seeks mainly student salary support, would thus enhance the use of new, modern facilities. Therefore, the proposed project provides excellent analytical and experimental experience for both graduate and undergraduate students. There is special focus on recruiting female students as well as students belonging to populations that are underrepresented in science and engineering and converting them into new graduate students. In addition, the principal investigator is Chief Technical Officer of Resonant Sensors Incorporated, a start-up company developing new sensor technology. As part of his duties under the Texas Instruments Chair, he will teach a yearly course on entrepreneurship and business, open to all undergraduate and graduate students, to stimulate innovation and technology transfer. The results of this research will be widely disseminated in journals and conferences. As there is currently a heavy worldwide emphasis on the study of periodic layers and lattices, new publications and results, illustrating the interesting effects and applications realized in the leaky-mode regime, might stimulate additional research and technological progress.

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)"

The objective of this research is integration of optical, electrical and mechanical systems at nano- and micro-meter scale, thus enabling novel biomedical, energy harvesting and structural health monitoring devices and systems, otherwise not possible. The approach is to use a wafer aligner and bonder system for precision alignment and bonding of a diverse set of substrates including semiconductor wafers, glass substrates, metals and polymers.

The intellectual merit lies in combining top-down and bottom-up fabrication techniques to pioneer new interfaces between semiconductor-based devices and biomolecules that can be tailored for specific applications, both as sensors and actuators / controllers of biological phenomena. The interrogation of bio-molecules and understanding of real cellular interactions require 3-D biocompatible structures, chambers and interfaces. Ranging in length scales from a few nanometers to many microns, inter and intra-cellular mechano-transduction signals play important roles in many aspects of cellular functions.

The proposed Precision Wafer Aligner / Bonder will be part of NanoFab at UT Arlington, which is an interdisciplinary resource open to scientists within and outside of the University. The Dallas-Forth Worth metropolitan region is home to more than 400 high tech institutions. As a user facility, the NanoFab will make the wafer aligner / bonder available 24/7 to these researchers and provide them training for usage. An annual workshop as well as an online discussion forum dedicated to 3-D integration will be established.

This PFI: AIR Technology Translation project focuses on translating research discoveries associated with a new class of wideband reflectors to fill the need for new photonic components in a broad variety of applications including laser manufacturing and infrared imaging systems. This innovation is important as new fundamental physical effects will be applied to enable solutions not attainable with current competing technology. The project will result in new designs and prototype reflectors that will be tested in detail for operation in important frequency bands. The proposed reflectors will have the following unique features: high degree of parametric stability, large spectral bandwidth, compact size, and high-yield manufacturing. These features provide advantages including high efficiency, low loss, economy in fabrication, and robustness in applications. These single-layer devices can be fabricated on substrates or as membranes. They avoid the multiple interfaces and associated issues in commercial thin-film multilayer reflectors; thus, thermal expansion effects and adhesion problems are minimized. These reflectors can be applied in spectral regions for which the deposition of thin-film multilayers is impractical or impossible. Therefore, this innovation provides new solutions and is likely to compete effectively in a sizeable market space.

This project addresses the following technology gaps as it translates from research discovery toward commercial application: (1) verification of the utility of the proposed fundamental resonance effect in this context, and (2) verification that practical prototype reflectors with high-efficiency wideband spectra can be fabricated. The proposed resonant reflectors are designed with gratings in which the grating ridges match to an identical material, thereby avoiding local reflections and phase changes. As this critical interface possesses zero refractive-index contrast, we call them "zero-contrast gratings." For simple gratings with two-part periods, we use numerical calculations to show that zero-contrast gratings provide extremely large flattop bandwidths and parametrically stable spectra; this project aims to demonstrate these devices experimentally. In summary, the main goals are to fabricate reflector prototypes operating in the ~1.2- to 12- micron spectral region; verify bandwidths of ~600-1100 nm with reflectance exceeding 99%; verify the predicted parametric stability; demonstrate polarized and unpolarized reflectors; and verify theoretical predictions of 99.99% reflectance for ~10- to 100-nm bandwidths. These devices are designed using powerful electromagnetic optimization algorithms, and they are made using standard nanofabrication methods including thin-film deposition, lithographic patterning, and etching. They are characterized by spectral analysis in the ~1- to 12- micron wavelength band. Hence, the project delivers compact, robust, polarized and unpolarized resonant reflectors that work within a broad spectral application space where classical methods fail to deliver effective solutions. In addition, personnel involved in this project, including undergraduate and graduate students, will receive entrepreneurial experiences, including business planning, by enrolling in "Engineering Entrepreneurship" that is taught by the PI on a regular basis.

EAGER: Development of ultra-sparse nanoscale resonant reflectors and polarizers

The objective of this proposal is to design, fabricate, and characterize wideband resonant reflectors and polarizers that require extremely small amounts of matter in their embodiments. Polarizers are essential components in every-day optical systems. They are used, for example, in liquid-crystal television screens and computer and cell-phone displays. Similarly, reflectors are widely used in optical imaging systems, telecommunications, and laser technology. Shown here is the remarkable and counterintuitive fact that a nanoscale periodic layer that is 95% empty space can reflect light at 100% efficiency across a 100-nm-wide spectral band. This simple device exhibits impressive polarizing performance as well. We call these elements ultra-sparse reflectors and polarizers. As these devices incorporate no metals, they are lossless and thus operate on incident light with high efficiency and without generating any heat. The project contributes to fundamental understanding of this class of devices and thereby lays foundation for its applications in common photonic systems. The proposed research project will focus on a spectral region spanning from the visible region into the infrared range where common telecommunication systems operate. However, it is noted that the fundamental physics of these elements does not limit their deployment to these regions. Hence, future developments in longer wavelength regions such as the far-infrared and terahertz bands may enable compact low-loss elements to be realized in these regions as well. The proposed project therefore lays a foundation for devices with new operational regimes and attendant possible applications in multiple practical spectral regions.

We introduce ultra-sparse reflectors and polarizers based on original new ideas in photonic device engineering. Under the project, prototype devices will be fashioned in nearly lossless semiconductors and dielectrics as membranes surrounded by air or glass host media. Initial focus is on spectral operation within the 400-2400 nm region. Using available nanofabrication processing facilities, we will fabricate representative devices as proof-of-concept prototypes, measure their spectral response, and compare with theoretical predictions. From a fundamental physics standpoint, it is extremely significant that the wideband spectral expressions presented can be generated in these minimal resonance systems. The proposed research is justified on that basis alone. Therefore, the project has strong potential to advance the state of knowledge and understanding in nanophotonic resonance systems. Contrary to widely accepted views, interference between two grating-ridge located Fabry-Perot modes is not the cause of the observed wideband reflection. Therefore, it follows logically that the number of such modes in a grating ridge is immaterial as far as the fundamental physics is concerned. We show that wideband reflectors are indeed achievable with a single supported ridge mode. This fact allows us to conceptualize resonant elements that are mostly free space with minimal physical bulk, an extremely interesting and important finding. To improve the state of understanding in this field, we plan on wide dissemination of the results of the research. This will broaden the design space available to scientists and engineers innovating within this device class.

Abstract title: Engineered nanoscale optical amplifiers and lasers

Nontechnical:
Silicon photonics is presently among the most active fields of research and development in optical science and technology. Importantly, silicon photonics is compatible with modern electronics technology on which everyday integrated circuit chips for computers and communications are based. Motivating this project, there is a need for useful and economic means for silicon-based light generation for silicon photonics technology. We plan to fill this void by engaging a unique optical resonance effect on nanostructured silicon films to generate light. Thus, we propose to develop new active devices, namely lasers and amplifiers, enabled by this fundamental effect. This can lead to new types of lasers serving as sources for silicon photonic chips as well as amplifiers for enhanced detection of incoming signals carried by light pulses as used in internet data transmission. Integrated photonic systems are expected to increase transmission and processing rates in optical communications. Under the project, we will evaluate the utility of fundamental photonic resonance effects, thus far not applied for this purpose, to enable advanced light generation in silicon. The project provides excellent analytical and experimental experience for graduate students thus supporting the development of the next-generation workforce in photonics technology. If successful, the project will led to innovative light generation and amplification concepts with substantial economic benefits and societal value.

Technical:
The objective of this research is to design, fabricate and characterize a new class of active nanophotonic guided-mode resonance elements. Specifically, we will investigate Raman amplifiers and lasers enabled by this effect. The research is motivated by the fact that Raman emission can be enhanced to high levels with these high-quality-factor resonance effects that are attainable in nanopatterned silicon films. We present preliminary device designs where the spectral placement of the pump and Raman lasing wavelengths achieves the proper Stokes-Raman shift in silicon. Here, the pump and lasing resonances have large quality factors with corresponding high Raman gain which is dominated by the product of the two factors. These elements will be fashioned as periodic nanostructures in the silicon-on-quartz and the silicon-on-insulator materials systems. We investigate fundamental aspects of the resonance interaction in these devices by computing emission spectra and attendant internal photonic field distributions including local field strengths. The fabricated devices will be characterized by electron-beam and atomic-force microscopy and their detailed spectral properties will be measured. The efficiency of the Stokes-Raman emission, including gain relative to pump, will be quantified relative to device architecture and input pump configuration. This project undertakes fundamental nanophotonic device research that is transformative, if successful, in view of potential applications in silicon photonics.

Abstract title: Band Flips and Bound States in Leaky-Mode Resonant Photonic Lattices

Nontechnical part
A photonic lattice is a periodic structure of materials with differing refractive indices. It is analogous to the familiar crystal lattice possessing a regular atomic arrangement. Photonic lattices effectively reflect, filter, and redirect incident light. Metamaterials constitute a new class of photonic lattices wherein principal performance metrics are controlled by the properties of a collection of subwavelength particles. Periodic and aperiodic metasurfaces and metagratings can be fashioned to provide complex functionality in extremely compact format even as single-layer films. Lossless dielectric media are particularly promising for high-efficiency applications. Thus, there is great interest in exploring metamaterials as building blocks for high-performance photonic devices including metalenses, perfect reflectors, and new types of holograms. Here, we propose to demonstrate new fundamental effects in nanophotonic resonance systems that are connected to asymptotic bound states in the spectral continuum. The new understanding generated under the project may lead to innovative ways to control light. The project provides excellent analytical and experimental experience for undergraduate and graduate students thus supporting the development of the next-generation workforce in photonics technology. If successful, the project will lead to innovative optical engineering ideas with substantial economic benefits and societal value.

Technical part
The objective of this research is to conduct research into band flips found to occur in leaky-mode photonic lattices. Their connection with non-leaky photonic states or bound states in the continuum (BIC) is of great interest. We seek solid physical understanding of these band flips and associated bound-state transitions and propose to demonstrate them experimentally with proof-of-concept prototypes. These elements will be fashioned as periodic nanostructures in nanocomposites with nanoimprint lithography allowing perfect control of spatial modulation, harmonic content, and spectral linewidths. We investigate fundamental aspects of the resonance interactions in these devices. The detailed spectral properties including band structure will be measured. Thus, we will treat photonic thin-film lattices supporting resonant leaky modes. Their properties include versatile spectra, polarization effects, substantial resonant Q-factors with strong local fields, and phase control. The band structure is unique supporting a leaky edge and a non-leaky edge for each supported resonant mode if the lattice is symmetric. The non-leaky edge is associated with a bound state in the continuum (BIC), or embedded eigenvalue, currently of great scientific interest. It is possible to control the width of the leaky band gap by lattice design. As a modal band closes, there results a quasi-degenerate state?this state is remarkable as it is possible to transit to it by parametric and material choice as shown in this proposal. It is possible to dither dynamically around this point with band-edge transitions into and out of the BIC dispersion branch. There are associated modulation and tuning possibilities. Using semianalytical and rigorous mathematical methods, we will characterize band flips and BICs relative to lattice harmonic content as this has great effect on the band properties. We will study BIC-generated passbands under leaky-mode band flips for the various mode bands. Moreover, we can implement band flips using double resonance structures with paired leaky-mode devices. When the devices are close to each other, the resonance bands interact via evanescent-wave coupling. This configuration possesses additional interference effects along with the band-transition and BIC properties of the simpler embodiments. Electrically induced coupling in and out of the bound continuum states might be possible. The new band-flip concept proposed here is unexplored with high potential impact in various branches of photonics along with exciting possibilities for new scientific discoveries.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

The broader impact/commercial potential of this PFI project is grounded in transformational new ideas for high-performance polarizers. These types of optical components are widely applied in practice, for example, in telecommunication systems, laser technology, medical sensor systems, television screens, and imaging instrumentation. The project lays a foundation for a pioneering device technology with new operational regimes and applicability. Simultaneously, the project enhances scientific and technological understanding by elucidating the optical properties and utility of lossless nanostructured resonant films on which the device concept is based. These research and development activities will strengthen US competitiveness in nanophotonics and metamaterials. Moreover, this project establishes partnerships between industry and academia. An academic team will provide device design specifications and prototype fabrication. A primary industrial partner will potentially distribute polarizes meeting specifications via existing sales and marketing platforms. The project provides excellent analytical and experimental experience for both graduate students and postdoctoral fellows. The project is likely to have high commercial impact, as the proposed patent-pending lossless polarizers with the predicted performance attributes do not currently exist in the market.

The proposed project delivers new polarizer technology based on original ideas in photonic device engineering. The intellectual merit of this technology lies in the novelty of our discovery that a sparse grid of dielectric nanowires is nearly completely invisible to one polarization state while being opaque to the orthogonal polarization state with this property existing over significantly wide spectral bands. It is scientifically extremely important that the high-efficiency, wideband spectra presented can be generated in these minimal resonance systems. Based on this discovery, our research objectives focus on design, fabrication and testing of compact, low-loss, dielectric polarizers for deployment in key spectral regions. Accordingly, we will design and fabricate simple single-layer elements as well as nanogrid multi-module lattices that provide excellent performance using a variety of practical materials. We plan complete spectral verification of the fabricated devices and comparison with theoretical predictions. We will measure polarization performance including bandwidth and extinction ratios in reflection and transmission of individual two-grating modules and of concatenated multilayer modules. Technical goals include high polarization extinction ratios of 1,000,000:1 and insertion loss below 1%. Manufacturing strategies involving high-resolution UV-laser interferometric patterning and carefully chosen materials will accomplish the goals of the project.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.