Photonics

Spatiotemporal Imaging Exploiting Structured Sparsity

Spatiotemporal imaging contains a large class of imaging problems, which involve collecting a sequence of data sets to resolve both the spatial and temporal (or spectral) distributions of some physics quantity. This capability is exploited in numerous different fields such as remote sensing, security surveillance systems, astronomical imaging, and biomedical imaging. One typical example is hyperspectral imaging, which is a powerful technology for remotely inferring the material properties of the objects in a scene of interest. Ultrasonic and thermal imaging are other important examples of spatiotemporal imaging where high spatial resolution is needed for urban planning, military planning, intelligence and disaster monitoring and evaluation.

Posted in: Briefs, Aerospace, Data Acquisition, Defense, Cameras, Imaging, Optics, Data Acquisition, Sensors
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Ultrafast Optics: Vector Cavity Lasers — Physics and Technology

Fiber lasers have found widespread applications in industrial material processing, scientific research and military systems due to their advantages of easy maintenance, excellent stability, compact size and low cost. One characteristic of fiber lasers, compared to other types of lasers, is that strong light is confined to propagating a long distance in a fiber core that has a very small cross-sectional area. This has the consequence that the nonlinear light interaction with the matter has a very long length. This results in the strength of all nonlinear optical processes being strongly amplified. This means that a conventionally weak, nonlinear optical effect can become significant. Therefore, apart from the practical applications, fiber lasers also constitute an ideal platform for the exploration of various complex nonlinear dynamics.

Posted in: Briefs, Aerospace, Defense, Fiber Optics, Lasers & Laser Systems, Optical Components, Optics, Photonics
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Integration of Adaptive Optics Into High-Energy Laser Modeling And Simulation

The U.S. Navy is constantly predicting future threats and contemplating new weapon technologies to counter them. One of those technologies is directed-energy (DE) weapons. Conventional weapons rely on the kinetic energy of projectiles. High-energy lasers (HELs), one type of directed-energy weapon, work in a fundamentally new way, using electromagnetic radiation to damage or destroy enemy assets.

Posted in: Briefs, Aerospace, Defense, Lasers & Laser Systems, Optics, Photonics, Simulation Software, Software
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3D Meta-Optics for High-Energy Lasers

The scope of this research radically changed the way novel components are designed and fabricated for high-energy applications. This 3D Meta-Optics platform was, and is, essentially engineering the electromagnetic fields in 3D dielectric structures. The results have provided a class of transformational optical components that can be integrated at all levels throughout a high-energy laser system.

Posted in: Briefs, Aerospace, Defense, Manufacturing & Prototyping, Materials, Lasers & Laser Systems, Optical Components, Optics, Test & Measurement
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Nominal High-Altitude Electromagnetic Pulse (HEMP) Waveforms

Even before the Trinity nuclear test in July of 1945, physicists predicted a transient electromagnetic signal would be caused by high-energy photons released from the detonation interacting with the air around the detonation. Predictions of these signals were difficult to make due to the complexity of the physics unleashed by the detonation.

Posted in: Briefs, Aerospace, Defense, Photonics, RF & Microwave Electronics, Instrumentation, Measuring Instruments, Test & Measurement
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Localization and Mapping of Unknown Locations with Unmanned Ground Vehicles

The main goals of this research are to enhance a commercial off-the-shelf (COTS) software platform to support unmanned ground vehicles (UGVs) exploring the complex environment of tunnels, to test the platform within a simulation environment, and to validate the architecture through field- testing.

Posted in: Briefs, Aerospace, Defense, Batteries, Cameras, Lasers & Laser Systems, Photonics, Automation, Robotics, Data Acquisition, Sensors, Simulation Software, Software, Transportation
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Simulation of Active Imaging Systems

Active imaging systems offer the promise of significantly improved tactical performance compared to passive military systems operating in adverse ground, air, and underwater/ maritime environments. These improvements would include, but are not limited to:

Posted in: Briefs, Aerospace, Data Acquisition, Defense, Imaging, Lasers & Laser Systems, Simulation Software
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Novel Characterization Methods for Anisotropic and Mixed-Conduction Materials

State-of-the-art electronic and optoelectronic devices require electronic materials with specialized properties that cannot be characterized with standard methods, or that must be characterized with extra precision. As a result of this research, the following new materials characterization methods have been developed:

Posted in: Briefs, Aerospace, Computers, Electronics, Electronics & Computers, Photonics
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Spatial Resolution and Contrast of a Focused Diffractive Plenoptic Camera

The concept of an imaging system that captures both spatial and spectral information has existed for a while. An example of one such imaging system that encodes both location and wavelength into an image is a Fourier Transform Spectrometer (FTS).

Posted in: Briefs, Aerospace, Cameras, Imaging, Optical Components, Optics
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Integrated Magneto-Optical Devices for On-Chip Photonic Systems

The magneto-optical (MO) oxide layer consists of (Bi,Y)3Fe5O12 or BiYIG, bismuth garnet. This material was selected because it has a better figure of merit than the CeYIG previously used, especially at lower wavelengths (1310 nm vs. 1550 nm). A top-down deposition process was developed in which BiYIG/YIG stacks are grown on the Si waveguide with YIG on top. The stack is annealed at 800°C/5 min to crystallize both layers, with the YIG templating the BiYIG leading to garnet phases rather than other oxides, and the BiYIG is directly on the Si waveguide. Initial attempts led to a film with Bi oxide phases, because the Bi was in excess and could not escape during the anneal as occurs in Si/YIG/BiYIG stacks. Hence the composition was adjusted to include slightly more Fe, which yielded films with only garnet peaks.

Posted in: Briefs, Aeronautics, Aerospace, Aviation, Electronic Components, Electronics, Electronics & Computers, Manufacturing & Prototyping, Materials, Optical Components, Optics, Photonics, Semiconductors & ICs
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