6,027 research outputs found

    Preventing Armageddon I: Enhancing America's Border & Port Security After 9/11; Strategic Insights, v. 3 issue 11 (November 2004)

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    This article appeared in Strategic Insights, v.3 issue 11 (November 2004)Approved for public release; distribution is unlimited

    Rapid Sensing of Hidden Objects and Defects using a Single-Pixel Diffractive Terahertz Processor

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    Terahertz waves offer numerous advantages for the nondestructive detection of hidden objects/defects in materials, as they can penetrate through most optically-opaque materials. However, existing terahertz inspection systems are restricted in their throughput and accuracy (especially for detecting small features) due to their limited speed and resolution. Furthermore, machine vision-based continuous sensing systems that use large-pixel-count imaging are generally bottlenecked due to their digital storage, data transmission and image processing requirements. Here, we report a diffractive processor that rapidly detects hidden defects/objects within a target sample using a single-pixel spectroscopic terahertz detector, without scanning the sample or forming/processing its image. This terahertz processor consists of passive diffractive layers that are optimized using deep learning to modify the spectrum of the terahertz radiation according to the absence/presence of hidden structures or defects. After its fabrication, the resulting diffractive processor all-optically probes the structural information of the sample volume and outputs a spectrum that directly indicates the presence or absence of hidden structures, not visible from outside. As a proof-of-concept, we trained a diffractive terahertz processor to sense hidden defects (including subwavelength features) inside test samples, and evaluated its performance by analyzing the detection sensitivity as a function of the size and position of the unknown defects. We validated its feasibility using a single-pixel terahertz time-domain spectroscopy setup and 3D-printed diffractive layers, successfully detecting hidden defects using pulsed terahertz illumination. This technique will be valuable for various applications, e.g., security screening, biomedical sensing, quality control, anti-counterfeiting measures and cultural heritage protection.Comment: 23 Pages, 5 Figure

    Vision Science and Technology at NASA: Results of a Workshop

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    A broad review is given of vision science and technology within NASA. The subject is defined and its applications in both NASA and the nation at large are noted. A survey of current NASA efforts is given, noting strengths and weaknesses of the NASA program

    The PLATO Dome A Site-Testing Observatory : instrumentation and first results

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    The PLATeau Observatory (PLATO) is an automated self-powered astrophysical observatory that was deployed to Dome A, the highest point on the Antarctic plateau, in 2008 January. PLATO consists of a suite of site-testing instruments designed to quantify the benefits of the Dome A site for astronomy, and science instruments designed to take advantage of the unique observing conditions. Instruments include CSTAR, an array of optical telescopes for transient astronomy; Gattini, an instrument to measure the optical sky brightness and cloud cover statistics; DASLE, an experiment to measure the statistics of the meteorological conditions within the near-surface layer; Pre-HEAT, a submillimeter tipping radiometer measuring the atmospheric transmission and water vapor content and performing spectral line imaging of the Galactic plane; and Snodar, an acoustic radar designed to measure turbulence within the near-surface layer. PLATO has run completely unattended and collected data throughout the winter 2008 season. Here we present a detailed description of the PLATO instrument suite and preliminary results obtained from the first season of operation

    Roadmap on optical security

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    Information security and authentication are important challenges facing society. Recent attacks by hackers on the databases of large commercial and financial companies have demonstrated that more research and development of advanced approaches are necessary to deny unauthorized access to critical data. Free space optical technology has been investigated by many researchers in information security, encryption, and authentication. The main motivation for using optics and photonics for information security is that optical waveforms possess many complex degrees of freedom such as amplitude, phase, polarization, large bandwidth, nonlinear transformations, quantum properties of photons, and multiplexing that can be combined in many ways to make information encryption more secure and more difficult to attack. This roadmap article presents an overview of the potential, recent advances, and challenges of optical security and encryption using free space optics. The roadmap on optical security is comprised of six categories that together include 16 short sections written by authors who have made relevant contributions in this field. The first category of this roadmap describes novel encryption approaches, including secure optical sensing which summarizes double random phase encryption applications and flaws [Yamaguchi], the digital holographic encryption in free space optical technique which describes encryption using multidimensional digital holography [Nomura], simultaneous encryption of multiple signals [Pérez-Cabré], asymmetric methods based on information truncation [Nishchal], and dynamic encryption of video sequences [Torroba]. Asymmetric and one-way cryptosystems are analyzed by Peng. The second category is on compression for encryption. In their respective contributions, Alfalou and Stern propose similar goals involving compressed data and compressive sensing encryption. The very important area of cryptanalysis is the topic of the third category with two sections: Sheridan reviews phase retrieval algorithms to perform different attacks, whereas Situ discusses nonlinear optical encryption techniques and the development of a rigorous optical information security theory. The fourth category with two contributions reports how encryption could be implemented at the nano- or micro-scale. Naruse discusses the use of nanostructures in security applications and Carnicer proposes encoding information in a tightly focused beam. In the fifth category, encryption based on ghost imaging using single-pixel detectors is also considered. In particular, the authors [Chen, Tajahuerce] emphasize the need for more specialized hardware and image processing algorithms. Finally, in the sixth category, Mosk and Javidi analyze in their corresponding papers how quantum imaging can benefit optical encryption systems. Sources that use few photons make encryption systems much more difficult to attack, providing a secure method for authentication.Centro de Investigaciones ÓpticasConsejo Nacional de Investigaciones Científicas y Técnica

    The Boston University Photonics Center annual report 2013-2014

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    This repository item contains an annual report that summarizes activities of the Boston University Photonics Center in the 2013-2014 academic year. The report provides quantitative and descriptive information regarding photonics programs in education, interdisciplinary research, business innovation, and technology development. The Boston University Photonics Center (BUPC) is an interdisciplinary hub for education, research, scholarship, innovation, and technology development associated with practical uses of light.This annual report summarizes activities of the Boston University Photonics Center in the 2013–2014 academic year.This has been a good year for the Photonics Center. In the following pages, you will see that the center’s faculty received prodigious honors and awards, generated more than 100 notable scholarly publications in the leading journals in our field, and attracted 14.5Minnewresearchgrantsandcontractsthisyear.Facultyandstaffalsoexpandedtheireffortsineducationandtraining,throughNationalScienceFoundation–sponsoredsitesforResearchExperiencesforUndergraduatesandforTeachers.Asacommunity,wehostedacompellingseriesofdistinguishedinvitedspeakers,andemphasizedthethemeofInnovationsattheIntersectionsofMicro/NanofabricationTechnology,Biology,andBiomedicineatourannualFutureofLightSymposium.Wetookaleadershiproleinrunningnationalworkshopsonemergingphotonicfields,includinganOSAIncubatoronControlledLightPropagationthroughComplexMedia,andanNSFWorkshoponNoninvasiveImagingofBrainFunction.HighlightsofourresearchachievementsfortheyearincludeadistinctivePresidentialEarlyCareerAwardforScientistsandEngineers(PECASE)forAssistantProfessorXueHan,anambitiousnewDoD−sponsoredgrantforMulti−ScaleMulti−DisciplinaryModelingofElectronicMaterialsledbyProfessorEnricoBellotti,launchofourNIH−sponsoredCenterforInnovationinPointofCareTechnologiesfortheFutureofCancerCareledbyProfessorCathyKlapperich,andsuccessfulcompletionoftheambitiousIARPA−fundedcontractforNextGenerationSolidImmersionMicroscopyforFaultIsolationinBack−SideCircuitAnalysisledbyProfessorBennettGoldberg.Thesethreeprograms,whichrepresentmorethan14.5M in new research grants and contracts this year. Faculty and staff also expanded their efforts in education and training, through National Science Foundation–sponsored sites for Research Experiences for Undergraduates and for Teachers. As a community, we hosted a compelling series of distinguished invited speakers, and emphasized the theme of Innovations at the Intersections of Micro/Nanofabrication Technology, Biology, and Biomedicine at our annual Future of Light Symposium. We took a leadership role in running national workshops on emerging photonic fields, including an OSA Incubator on Controlled Light Propagation through Complex Media, and an NSF Workshop on Noninvasive Imaging of Brain Function. Highlights of our research achievements for the year include a distinctive Presidential Early Career Award for Scientists and Engineers (PECASE) for Assistant Professor Xue Han, an ambitious new DoD-sponsored grant for Multi-Scale Multi-Disciplinary Modeling of Electronic Materials led by Professor Enrico Bellotti, launch of our NIH-sponsored Center for Innovation in Point of Care Technologies for the Future of Cancer Care led by Professor Cathy Klapperich, and successful completion of the ambitious IARPA-funded contract for Next Generation Solid Immersion Microscopy for Fault Isolation in Back-Side Circuit Analysis led by Professor Bennett Goldberg. These three programs, which represent more than 20M in research funding for the University, are indicative of the breadth of Photonics Center research interests: from fundamental modeling of optoelectronic materials to practical development of cancer diagnostics, from exciting new discoveries in optogenetics for understanding brain function to the achievement of world-record resolution in semiconductor circuit microscopy. Our community welcomed an auspicious cohort of new faculty members, including a newly hired assistant professor and a newly hired professor (and Chair of the Mechanical Engineering Department). The Industry/University Cooperative Research Center—the centerpiece of our translational biophotonics program—continues to focus on advancing the health care and medical device industries, and has entered its fourth year of operation with a strong record of achievement and with the support of an enthusiastic industrial membership base

    The Boston University Photonics Center annual report 2013-2014

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    This repository item contains an annual report that summarizes activities of the Boston University Photonics Center in the 2013-2014 academic year. The report provides quantitative and descriptive information regarding photonics programs in education, interdisciplinary research, business innovation, and technology development. The Boston University Photonics Center (BUPC) is an interdisciplinary hub for education, research, scholarship, innovation, and technology development associated with practical uses of light.This annual report summarizes activities of the Boston University Photonics Center in the 2013–2014 academic year.This has been a good year for the Photonics Center. In the following pages, you will see that the center’s faculty received prodigious honors and awards, generated more than 100 notable scholarly publications in the leading journals in our field, and attracted 14.5Minnewresearchgrantsandcontractsthisyear.Facultyandstaffalsoexpandedtheireffortsineducationandtraining,throughNationalScienceFoundation–sponsoredsitesforResearchExperiencesforUndergraduatesandforTeachers.Asacommunity,wehostedacompellingseriesofdistinguishedinvitedspeakers,andemphasizedthethemeofInnovationsattheIntersectionsofMicro/NanofabricationTechnology,Biology,andBiomedicineatourannualFutureofLightSymposium.Wetookaleadershiproleinrunningnationalworkshopsonemergingphotonicfields,includinganOSAIncubatoronControlledLightPropagationthroughComplexMedia,andanNSFWorkshoponNoninvasiveImagingofBrainFunction.HighlightsofourresearchachievementsfortheyearincludeadistinctivePresidentialEarlyCareerAwardforScientistsandEngineers(PECASE)forAssistantProfessorXueHan,anambitiousnewDoD−sponsoredgrantforMulti−ScaleMulti−DisciplinaryModelingofElectronicMaterialsledbyProfessorEnricoBellotti,launchofourNIH−sponsoredCenterforInnovationinPointofCareTechnologiesfortheFutureofCancerCareledbyProfessorCathyKlapperich,andsuccessfulcompletionoftheambitiousIARPA−fundedcontractforNextGenerationSolidImmersionMicroscopyforFaultIsolationinBack−SideCircuitAnalysisledbyProfessorBennettGoldberg.Thesethreeprograms,whichrepresentmorethan14.5M in new research grants and contracts this year. Faculty and staff also expanded their efforts in education and training, through National Science Foundation–sponsored sites for Research Experiences for Undergraduates and for Teachers. As a community, we hosted a compelling series of distinguished invited speakers, and emphasized the theme of Innovations at the Intersections of Micro/Nanofabrication Technology, Biology, and Biomedicine at our annual Future of Light Symposium. We took a leadership role in running national workshops on emerging photonic fields, including an OSA Incubator on Controlled Light Propagation through Complex Media, and an NSF Workshop on Noninvasive Imaging of Brain Function. Highlights of our research achievements for the year include a distinctive Presidential Early Career Award for Scientists and Engineers (PECASE) for Assistant Professor Xue Han, an ambitious new DoD-sponsored grant for Multi-Scale Multi-Disciplinary Modeling of Electronic Materials led by Professor Enrico Bellotti, launch of our NIH-sponsored Center for Innovation in Point of Care Technologies for the Future of Cancer Care led by Professor Cathy Klapperich, and successful completion of the ambitious IARPA-funded contract for Next Generation Solid Immersion Microscopy for Fault Isolation in Back-Side Circuit Analysis led by Professor Bennett Goldberg. These three programs, which represent more than 20M in research funding for the University, are indicative of the breadth of Photonics Center research interests: from fundamental modeling of optoelectronic materials to practical development of cancer diagnostics, from exciting new discoveries in optogenetics for understanding brain function to the achievement of world-record resolution in semiconductor circuit microscopy. Our community welcomed an auspicious cohort of new faculty members, including a newly hired assistant professor and a newly hired professor (and Chair of the Mechanical Engineering Department). The Industry/University Cooperative Research Center—the centerpiece of our translational biophotonics program—continues to focus on advancing the health care and medical device industries, and has entered its fourth year of operation with a strong record of achievement and with the support of an enthusiastic industrial membership base
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