University System of Maryland

Other

Johns Hopkins University

Spessard Manufacturing, LLC

Christopher C Davis

Igor I Smolyaninov

Saeed Pilevar

John Robertson Rzasa

Walid A Atia

Frank H Portugal

Stuart D Milner

Alexander J Fielding

Klaus Edinger

David M Brown

Raul Fainchtein

Gerald W Spessard

Jaime Llorca

David L Mazzoni

Kyman Cho

Richard B Wagreich

Yu-Ju Hung

Chensheng Wu

Daniel Paulson

Leroy B Chamberlain, Jr

Anatoly Zayats

Jonathan Ko

Jakob R Scharmer

An afocal sensor assembly detects a light beam with an aberrated wavefront. The afocal sensor assembly is configured to provide sorted four-dimensional (4D) light field information regarding the light beam, for example, via one or more plenoptic images. Based on the 4D light field information, a lossy reconstruction of an aberrated wavefront for one or more actuators of an adaptive optics (AO) device is performed. The AO device can be controlled based on the lossy reconstruction to correct the wavefront of the light beam. In some embodiments, the aberrated wavefront is due to passage of the light beam through atmospheric turbulence, and the lossy reconstruction and correction using the AO device is performed in less than 1.0 ms. The lossy reconstruction of the aberrated wavefront can have a phase accuracy in a range of λ/2 to λ/30.

Light field-based beam correction systems and methods

An electronic home plate provides assistance to an umpire in determining whether a pitch results in a 'strike' or a 'ball.' The home plate is implemented with LEDs producing discrete pulses of infrared light beams extending vertically. As a moving ball intersects the pulses, light from the pulses is scattered and incident on photodetectors embedded in the home plate, producing a series of data points. Two stages of light compensation compensate the data points for ambient light, first by applying an offset current to a photodetector through a PNP transistor, and second by subtracting a measurement immediately before a pulse from a measurement during the pulse. A processor then fits the data points to a curve, to compute vertical and lateral positions of the ball, thereby determining whether the pitch passed within a strike zone. Other applications may similarly analyze the trajectory of other projectiles for various purposes.

Projectile position measurement using non-linear curve fitting

An electronic home plate providing assistance to an umpire in determination whether a pitch results in a 'strike' or a 'ball'. The electronic home plate is implemented with eye-safe LEDs producing light beams extending vertically. If a ball intersects the light beams, the light reflected from the ball is scattered and incident on photodetectors embedded in the home plate. A microcomputer embedded in the electronic home plate calculates the height of the ball crossing the light beams, and if the height falls between the top and bottom boundaries of a strike zone adjusted to the height of the batter, an indication system is activated to produce a &#x201c;strike&#x201d; signal. The microcomputer in the electronic home plate is further configured to calculate speed of the ball passing over the home plate, and the lateral position of the ball.

Electronic home plate for baseball and softball games and method for automatic determination of presence, position and speed of a ball relative to the strike zone

Systems, methods, devices, and computer program products are directed to mobility control and performance prediction in directional wireless networks. Network coverage and connectivity are optimized. Convex and non-convex network modeling is implemented to provide adaptive topology control and mobility control within the network, whereby communication links are retained, released, or reconfigured based on their communication role within the network architecture. Optionally or alternatively, network health is monitored, future network failure or degradation conditions are predicted, and the network reconfigures responsive to the predictions to avoid the failure or degradation conditions.

Systems, methods, devices, and computer program products for control and performance prediction in wireless networks

An infrared (IR) scene projector device includes a light emitter and a thermal emitter. The light emitter is configured to selectably provide visible light. The thermal emitter includes a vertically aligned carbon nanotube (VACN) array. The VACN array includes a plurality of carbon nanotubes disposed proximate to a thermally conductive substrate, such that a longitudinal axis of the carbon nanotubes extends substantially perpendicular to a surface of the substrate. The thermal emitter absorbs the visible light from the light emitter and converts the visible light from the light emitter into IR radiation.

Agile IR scene projector

In a sensor system, an active sensor chip includes an array of periodically-patterned dielectric active sensor patches of different periodicities and geometries formed on a metal film. A specimen under study is positioned on each patch, and the active sensor chip is interrogated by illumination the patches in a predetermined sequence to result in a fluorescence response from each patch enhanced by SPP. The intensity of the fluorescence response is controlled by varying the wavelength, incidence angle, azimuthal orientation and polarization direction of the excitation light beam as the function of the periodicity of the illuminated patch. The system is compatible with commercial fluorescence microscopes and scanned laser interrogation systems.

Sensor system with surface-plasmon-polariton (SPP) enhanced selective fluorescence excitation and method

A far-field optical microscope capable of reaching nanometer-scale resolution using the in-plane image magnification by surface plasmon polaritons is presented. The microscope utilizes a microscopy technique based on the optical properties of a metal-dielectric interface that may, in principle, provide extremely large values of the effective refractive index nup to 10-10as seen by the surface plasmons. Thus, the theoretical diffraction limit on resolution becomes &#x3bb;/2n, and falls into the nanometer-scale range. The experimental realization of the microscope has demonstrated the optical resolution better than 50 nm for 502 nm illumination wavelength.

Far-field optical microscope with a nanometer-scale resolution based on the in-plane image magnification by surface plasmon polaritions

Far-field optical microscope with a nanometer-scale resolution based on the in-plane image magnification by surface plasmon polaritons

A system and method for optical wireless communication with fading resistance. A delayed diversity approach reduces fading significantly. Data is sent in a set of light signals (also called diverse light signals) which each have a different polarization and/or a different wavelength. The diverse light signals are also temporally different in that they are transmitted in a delayed fashion with respect to one another. In this way, each light signal is carried over a different, uncorrelated 'channel' through the atmosphere. At a receiver, original data in each received light signals is temporally adjusted and combined into a single output data signal. The accuracy of each bit in the output data signal is then due to the reception of the combined diverse light signals. In this way, even if fading occurs in one channel (effecting one diverse light signal), a combined output data signal can still be generated at relatively high accuracy from the original data carried in one or more of the other diverse light signals.

System and method for optical wireless communication

In a free space communication network in which different communication nodes are linked together by directed beams, a method for dynamically configuring the topology of the network allows the transmission directions of the communication nodes to be autonomously changed to communicate with a new node as dictated by the needs of the network. Moreover, the nodes can be switched from directional to broadcast and back again on an as-needed basis. The network consists of a topology that can be rapidly and physically reconfigured as required to provide multiple connectivity, a desired quality of service, or to compensate with the loss of communication links between nodes. The loss of direct communication between any two nodes in an optical network can occur because of obscuration of the atmospheric path between the two nodes. The directed beam which provides the communication channel between the two nodes can, in this situation, be steered to direct its energy towards another accessible node.

Optical wireless networks with adjustable topologies

A system () for optical processing based on light-controlled photon tunneling is provided. The system () includes a prism () having a metallic film layer () formed on an upper surface thereof. The metallic film layer () has a microscopic aperture () formed therethrough and the microscopic aperture () is covered by a layer of non-linear optical film. A first light beam () is projected towards aperture () and photons from first light beam () tunnel through aperture (). A second light beam () is also projected towards microscopic aperture (), with the second light beam () having a different wavelength than that of light beam (). Selective actuation and modulation of light beam () allows for selective control over the rate and intensity of the photons which tunnel through microscopic aperture (). The intensity of transmission of the photons from light beam () are measured by optical fiber tip (), thus allowing for the creation of optical gates, switches, and other optical processing devices.

System and method for optical processing based on light-controlled photon tunneling

A method of forming a fiber probe having an aperture for use in near-field scanning optical microscopy. The method includes a first steps of coating an optical fiber having a tapered tip with a metal layer. Next is a step of milling the tapered tip and metal layer such that an aperture is formed through the metal layer at the tapered tip. The milling step includes focused ion-beam milling the tapered tip and metal layer. The focused ion-beam milling can be done by raster scanning the focused ion-beam in a rectangular pattern at an apex of the tapered tip. Also, the fiber probe made through the above outlined method is used in near-field scanning optical microscopy.

Focused ion-beam fabrication of fiber probes for use in near field scanning optical microscopy

An optical fiber is tapered, preferably adiabatically, and has a material coated on it for chemical bonding with fluorophores. When the fluorophores couple with the material, evanescent radiation generated fibers causes the fluorophores to fluoresce, and the fluorescence is coupled back into the fiber.

Optical fiber evanescent field excited fluorosensor and method of manufacture

Optical fiber evanescent field excited fluorosensor and method of

A probe includes first and second single-mode optical fibers with a semi-reflecting mirror between them. The second optical fiber is tapered by heating and pulling. The semi-reflecting mirror, the tapered portion, and the sample form a Fabry-Perot cavity. The probe can be used in a system having a differential interferometer which provides the appropriate path difference with a mirror on a piezoelectric transducer.

Growing community of inventors

Bowie, MD, United States of America

Christopher C Davis