US Government As Represented by the Secretary of the Army

USA As Represented by Secretary of the Navy

Kristan Peter Gurton

Gorden W Videen

Leonid Alexseevich Beresnev

Nathaniel Jackson Short

Chatt C Williamson

David A Ligon

Shuowen Hu

Steven Clyde Hill

Richard Kounai Chang

Yongle Pan

Ronald Gene Pinnick

Anthony R Valenzuela

Alex Lipchen Chan

James B Gillespie

Yong-Le Pan

Alexey J Yuffa

Mark Dubinskiy

Angel S Flores

Kevin Bruce Aptowicz

Alex J Yuffa

A method and apparatus for controlling propagation of a light beam using a beveled endcap of an optical fiber, where the endcap has a first end coupled to the optical fiber and a second end having a bevel that circumscribes a facet. The bevel has an angle relative to the plane of the facet that directs a peripheral portion of the light beam towards a lens and the facet directs a central portion of the light beam towards the lens. As such, the light beam is collimated with substantially all of the power of the light beam propagating through the lens and all the power delivered with fiber core to the output endcap is propagating through the lens despite the divergence of the delivered beam and a restricted aperture of the lens.

Fiber optic collimator with a beveled fiber endcap

A method, apparatus and system for coherent beam combining (CBC) in high energy fiber laser (HEL) systems include generating a reference interference pattern of a signal source including at least two single-mode optical signals, capturing and evaluating the reference interference pattern, maximizing an intensity of the selected area of the captured, reference interference pattern, increasing a linewidth of the optical signals generating the reference interference pattern until the reference interference pattern is degraded, and adjusting a delay time of one of the at least two single-mode optical signals until the reference interference pattern is recovered, by adjusting a value of a delay of a delayed RF signal with a broaden linewidth to a respective EO linewidth broadening modulator in at least one channel of the at least two single-mode optical signals while evaluating the interference pattern on a display device.

Systems, apparatuses and methods for coherent beam combining of fiber laser beams with broadened linewidth

Object/facial recognition systems, methods, architectures, mechanisms and/or apparatus for 3D face or object recognition using a 3D surface reconstructed from polarimetric thermal facial/object imager to form a 2D or 3D image which is rotated to conform with a pose of a reference image to allow comparison thereto.

3D polarimetric face recognition system

A method and apparatus for cross-modal matching with polarimetric thermal image data is provided. According to one embodiment, the method comprises receiving a plurality of polarimetric thermal images of a face acquired by a polarimetric thermal imaging camera, extracting features of the face from each of the plurality of images to generate a plurality of feature vectors for each of the plurality of images, compositing the feature vectors for each of the plurality of images together to form composite feature vectors and cross-modally matching the composite feature vectors with other feature vectors, in order to determine whether the face matches a face represented by the other feature vectors.

Method of apparatus for cross-modal face matching using polarimetric image data

A method and apparatus is provided for modeling a three-dimensional topological surface of an object acquiring, using a thermal imaging camera, a first image of the object, wherein the first image comprises a plurality of pixels each representative of at least one component of thermal data, calculating a normal vector for each pixel in the first image, corresponding to the normal vector on a surface of the object, generating a three-dimensional model representing a surface of the object based on aggregating the normal vector for each pixel together in the first image.

Method for modeling a three-dimensional topological surface of an object from long-wave-infrared radiation emitted from the object

A method and system for detecting composition of a physical space comprising: a laser beam source; an acoustic sensor; a beam focusing mechanism for focusing the laser beam at predetermined points in the physical space to generate a thermal inhomogeneity which results in the propagation of a pressure wave that propagates outward from the predetermined excitation point at a propagation velocity approximating the speed of sound for the particular composition of the media; at least one processor for controlling the timing for the laser beam focusing to generate thermal inhomogeneities; whereby the laser focal point is moved sequentially along the light-of-sight at various excitation points by the beam focusing mechanism approximately at the phase front velocity to define a series of predetermined excitation points and pressure wave propagations such that the series of pressure wave propagations combine to produce a coherent pressure wave detectable by the acoustic sensor.

Remote sensing using coherent sonic wave photoacoustic detection and methods

A detector assembly for detecting a flash from the firing of a weapon comprising: a first support; a plurality of sensors supported by the first support for detecting light from the flash; the sensors operating to receive light in the range of ultraviolet light from approximately 100 nm to approximately 290 nm; a directional indicator for indicating the directional location of the first support; and an indicator assembly comprising at least one indicator; the at least one indicator operating to display the directional location of the flash.

Body mounted detector and method for detecting flash in solar blind ultraviolet spectral region

Embodiments of photoacoustic devices, systems, and methods are disclosed. One device embodiment, among others, comprises a flow-through configuration for a test sample gas and a modular set of two or more solid-state or gaseous based lasers.

Flow-through aerosol photoacoustic systems and methods

Characterizing individual airborne particles in real time according to their absorption of optical energy at one or more wavelengths. The instrument can measure the two-dimensional angular optical scattering (TAOS) and/or the one-dimensional angular optical scattering (ODAOS) at one or more wavelengths. When two wavelengths are used, one is chosen to be on an absorption peak, the other is off of the absorption peak (preferably in the absorption valley).

Method and instrumentation for determining absorption and morphology of individual airborne particles

An apparatus for detecting a trip wire includes a point source of light of a given wavelength; a mirror that reflects the point source of light, the mirror having a first frequency of oscillation about a first axis to thereby create an appearance of a continuous line, the mirror having a second frequency of oscillation about a second axis to thereby define a planar surface, the first frequency of oscillation being greater than the second frequency of oscillation; a camera offset from the point source of light such that a field of view of the camera does not intersect the planar surface, the camera receiving light reflected from the trip wire; and a computer connected to the camera, the computer including pattern recognition algorithms for analyzing the light reflected from the trip wire and thereby detecting a presence of the trip wire.

Optical technique for the detection of suspended trip-wires and cables

A single particle photoacoustic absorption spectrometer for directly measuring the absorption spectra for in situ individual aerosol type particles that is comprised of an electrodynamic trap capable of suspending a charged particle in free-space in a non-intrusive manner; a source of modulated monochromatic electromagnetic radiation, e.g., a laser, and an acoustic transducer/resonator for detecting/amplifying sound waves emitted by the irradiated particle. Depending on the characteristics of the particle, a certain fraction of the electromagnetic energy will be absorbed by the particle resulting in its rapid heating and cooling at the modulation frequency. The heat generated within the particle is rapidly transferred to the surrounding air resulting in a sound wave. The intensity of the sound wave is proportional the absorbed energy by the particle. The wavelength of the monochromatic electromagnetic source is then shifted slightly and the measurement is repeated until the desired absorption spectra are completely recorded.

Single particle photoacoustic absorption spectrometer

A single particle caloric absorption spectrometer for directly measuring the absorption spectra in situ of individual aerosol type particles comprises a differential arrangement of two identical electrodynamic traps (separated by a series of pneumatic valves) capable of suspending a charged particle in free-space in a non-intrusive manner in one of the traps; a source of monochromatic radiation, e.g., a laser, which is split and directed equally through transmission windows into the traps; and, a high precision capacitance manometer capable of detecting the pressure differential between the traps. After a particle has been trapped in one of the traps and the traps have been sealed from the atmosphere and from each other by the pneumatic vales, the radiation source is turned on and is evenly split/directed into both trap volumes via an appropriate beam splitter and transmission windows. This results in identical illumination of both the target and reference trap regions. A certain fraction of energy will be absorbed by the particle resulting in its heating. The heat generated within the particle is rapidly transferred to the surrounding air resulting in a net change in pressure between the target and reference traps. This change in pressure is recorded by the capacitance manometer and is shown to be proportional to the actual absorption cross section of the particle. The wavelength of the laser is then shifted slightly and the measurement is repeated until the desired spectra are completely recorded.

Growing community of inventors

Olney, MD, United States of America

Kristan Peter Gurton