Trw Limited

Northrop Grumman Systems Corporation

Peter Moshchansky Livingston

Robert R Rice

Alvin D Schnurr

Michael G Wickham

Hiroshi Komine

Peter Anthony Thielen

Jonathan W Arenberg

Jerold L Jacoby

Joseph W Austin

Charles Phillip Asman

John Nella

Lihong Wang

Jean C Shelton

Systems and methods are provided for reducing the storage time of spent nuclear fuel. In one embodiment, a method is provided that includes providing a sample of spent nuclear fuel and irradiating the spent nuclear fuel with substantially collimated gamma ray photons having energy levels of about 10 MeV to about 15 MeV for a predetermined time period to initiate a photofission reaction in the remaining fertile fissile material in the spent nuclear fuel.

Systems and methods for reducing the storage time of spent nuclear fuel

A method is provided for forming an optical fiber amplifier. The method comprises providing a composite preform having a gain material core that includes one or more acoustic velocity varying dopants to provide a longitudinally varying acoustic velocity profile along the gain material core to suppress Stimulated Brillouin Scattering (SBS) effects by raising the SBS threshold and drawing the composite preform to form the optical fiber amplifier.

Optical fiber amplifier and methods of making the same

A high-power laser system includes a laser master oscillator, a plurality of fiber laser amplifiers producing intermediate output beamlets, a diffractive optical element for combining the intermediate beamlets into a combined output beam, and a piston error controller for minimizing errors related to beam combination that may degrade the quality of the combined output beam. A piston error controller uses amplitude modulation based on Hadamard code words to tag each non-reference intermediate beamlet with a unique code sequence orthogonal to those used for the other beamlets. For each intermediate beamlet, the associated piston error contribution is recovered using a Hadamard decoder. A very small phase dither is also introduced to allow the sign or direction of the piston error to be recovered. The decoded piston error contribution is processed by a cascaded product detector unit to derive a piston error control signal, which is provided to a phase modulator to thereby adjust the phase of a beamlet and minimize the piston error contributed thereby.

Digital piston error control for high-power laser system employing diffractive optical element beam combiner

Systems and methods for generating electromagnetic waves are provided. In one embodiment, a system for generating electromagnetic waves is provided. The system comprises a dielectric column comprising a spherical portion and at least one cylindrical portion, wherein the spherical portion receives a first wave from a first source and a second wave from a second source and generates a resulting electromagnetic wave along the interior of the cylindrical portion having a difference frequency caused by whispering gallery modes of the spherical portion, and the at least one cylindrical portion having at least one output for outputting the resulting electromagnetic wave.

Systems and methods for generating electromagnetic radiation

A high-power laser system includes a laser master oscillator, a plurality of fiber laser amplifiers producing intermediate output beamlets, a combiner for combining the intermediate beamlets into a combined output beam, and a piston error controller for minimizing errors related to beam combination that may degrade the quality of the combined output beam. A piston error controller processes a sample of the combined output beam using a Diffractive Optical Element to isolate a signal representing the total piston error of the combined beam. The controller uses amplitude modulation based on Hadamard code words to tag each non-reference intermediate beamlet with a unique code sequence orthogonal to those used for the other beamlets. For each intermediate beamlet, the associated piston error contribution is recovered using a Hadamard decoder. A very small phase dither is also introduced to allow the sign or direction of the piston error to be recovered. The decoded piston error contribution is processed by a cascaded product detector unit to derive a piston error control signal, which is provided to a phase modulator to thereby adjust the phase of a beamlet and minimize the piston error contributed thereby.

Diffractive method for control of piston error in coherent phased arrays

A high-power laser system includes a laser master oscillator, a plurality of fiber laser amplifiers producing intermediate output beamlets, a diffractive optical element for combining the intermediate beamlets into a combined output beam, and one or more error controllers for minimizing errors related to beam combination that may degrade the quality of the combined output beam. A piston error controller uses phase modulation to tag each non-reference intermediate beamlet with a unique dither signal harmonically unrelated to those used for the other beamlets. For each intermediate beamlet, the associated piston error is recovered using a synchronous detector, and an error control signal proportional to the piston error is supplied to a phase modulator to control the piston error for that beamlet. A tilt error controller uses amplitude modulation based on Hadamard code words to tag each non-reference intermediate beamlet with a unique code sequence orthogonal to those used for the other beamlets. For each intermediate beamlet, the associated tilt error is recovered using a Hadamard decoder, and an error control signal proportional to the tilt error is supplied to a beam steerer to control the tilt error for that beamlet.

Error control for high-power laser system employing diffractive optical element beam combiner with tilt error control

Error control for high-power laser system employing diffractive optical element beam combiner

Apparatus, and a related method, for eliminating the effect of speckle images caused by surface imperfections in a primary mirror of a stellar coronagraph. Depending on their size, mirror imperfections can result in speckles in a field of view that also includes an image of a distant target planet. By generating a traveling surface wave in the mirror surface, and then tuning the spatial wavelength of the surface wave to approximately match that of a surface imperfection, the speckle image corresponding to that surface imperfection is made to twinkle in irradiance. Tuning the traveling surface wave though a wide range of spatial wavelengths causes each speckle image in turn to be identified by twinkling, while the target planetary image remains unvarying. Accordingly, multiple speckles corresponding to different mirror imperfections may be conveniently eliminated by image processing.

Distinguishing mirror speckle from target images in weak signal applications

An imaging or viewing system, which automatically compensates for bright spots, which tend to overload or saturate imaging system. The system can be used with imaging type tracking systems, viewers and various types of optical devices which heretofore have been unable to provide satisfactory performance due to saturation or overloading of an imaging device due to bright spots, i.e., laser radiation flares or sunlight. The system in accordance with the invention is configured such that reflected radiation is imaged onto a first image plane without dividing the incoming radiation into two optical paths. A digital mirror device, i.e., is disposed at the first image plane. The radiation level of each pixel in the image plane is compared with a fixed threshold on a pixel by pixel basis and used to generate a mirror drive signal that automatically reduces the reflectivity of the corresponding mirror pixel to compensate for bright spots.

Means for protecting optical focal plane sensor arrays against excessive irradiation

A detector for detecting infrared photons is disclosed. It comprises an anode, a cathode including a plurality of nanotubes formed from carbon and means for electrically connecting the nanotubes, and bias circuitry for applying an electric field between the anode and the cathode such that when infrared photons are absorbed by the nanotubes, photoelectrons are created. A gate electrode is disposed between the anode and the cathode and controls the passage of the photoelectrons passing therethrough. A pulse height analyzer separates photoelectrons from electrons created by field emission from the nanotubes and serves to measure the photoelectrons.

Infrared carbon nanotube detector

An imaging self-referencing target tracker ( ) for a laser weapon ( ). The weapon generates a first beam of radiation ( ) that engages a target ( ) to form a beam hit spot ( ) thereon. In a first embodiment, a target illuminator ( ) (variant ) illuminates the target with a second beam of radiation ( ). An optics subsystem ( ) receives and separately images the first and second beams ( ) of radiation. In a second embodiment, a blocking filter ( ) is implemented rather than an illumination laser to pass only radiation at the target wavelength, thereby ensuring that the first and second beams of radiation are separately imaged. A controller ( ) is programmed to steer the first and second beams of radiation to the desired target aim point ( ) in response to information from the imaged first and second beams of radiation. The tracker of the present invention tracks the laser hit spot relative to the actual target image in a closed loop manner, thereby increasing the probability of accurate target engagement and resulting in a target kill.

Shared aperture dichroic active tracker with background subtraction

A method and device for determining concentration and rate of change of concentration of a gas having ability to act as crystal etchant, such as hydrofluoric acid (HF) or deuterium fluoric acid (DF) gas. A crystal,is placed in a chamber and subjected to erosion by the gas. The crystal resonant frequency, changeable during the crystal erosion, is determined and a crystal resonant frequency change is calculated to determine the concentration of the gas. The crystal,is preferably an AT-cut quartz crystal. The step of obtaining the crystal resonant frequency is preferably performed in a Colpitts oscillator. The step of calculating the gas concentration, proportional to the change in the crystal resonant frequency, may also encompass calculating a change and rate of change in the gas concentration, and averaging the calculated gas concentration. The crystal,is preferably inserted in a crystal holder,and mounted on an electronic box,which holds the oscillator board. The crystal,is partially protected with a cover,and is easily replaceable.

Simple and inexpensive method and device for measuring concentration and rate of change of a crystal etchant gas, such as HF or DF gas

A laser tracking system steers a beam of laser energy which is dithered in two directions to scan the surface of a moving object. A laser energy detector detects laser energy reflected from the target. Reflected energy is filtered to distinguish dither frequencies for signals in both directions, which signals are independently analyzed to determine the location of the target in relation to the laser beam. A bias signal is generated which causes the beam of laser energy to be steered toward a surface radius to be steered toward a surface with the largest compound curvature within the trackers, field-of-regard, to the target, to the tracked location on-target, or modified signals steer a portion of the beam to an optimum track location on target while offsetting most of the beam's energy to a second engagement location on target. Also, a track testing system is capable of monitoring a laser beam focused on a missile and determining the effective laser engagement on a spinning target.

Tracking means for distant ballistic missile targets

An imaging self-referencing target tracker (,) for a laser weapon (,). The weapon generates a first beam of radiation (,) that engages a target (,) to form a beam hit spot (,) thereon. In a first embodiment, a target illuminator (,) (variant,) illuminates the target with a second beam of radiation (23,). An optics subsystem (,) receives and separately images the first and second beams (23,24) of radiation. In a second embodiment, a blocking filter (,) is implemented rather than an illumination laser to pass only radiation at the target wavelength, thereby ensuring that the first and second beams of radiation are separately imaged. A controller (,) is programmed to steer the first and second beams of radiation to the desired target aim point (,) in response to information from the imaged first and second beams of radiation. The tracker of the present invention tracks the laser hit spot relative to the actual target image in a closed loop manner, thereby increasing the probability of accurate target engagement and resulting in a target kill.

Shared aperture dichroic tracker with background subtraction

A resonant absorption cell filled with a gas, selected in accordance with the wavelength of the laser radiation of interest, such as DF. The gas within the cell is maintained at substantially atmospheric pressure. The energy state of the gas within the cell is raised by either external resistance heating or optical pumping. In an increased energy state, gas molecules resonate with the incoming laser radiation causing the molecules to absorb incident photons before the gas molecules have a chance to re-radiate the captured photons, collisions with other gas molecules within the cell transfer the excitation energy into heat in order to filter out laser radiation but past all other wavelengths.

Growing community of inventors

Palos Verdes Estates, CA, United States of America

Peter Moshchansky Livingston