Raytheon Company

Maurice J Halmos

Joseph C Marron

David N Sitter, Jr

Gamze Erten

Justin S Grayer

Fabio Di Teodoro

Jean-Paul Bulot

Matthew J Klotz

Jae H Kyung

Benjamin P Dolgin

Andrew M Kowalevicz

Gary M Graceffo

Robert D Stultz

Joseph J Ichkhan

Todd O Clatterbuck

Tim P Johnson

Kyle Heideman

Louis F Klaras

John Edgecumbe

Jr David N Sitter

Methods and apparatus for optical beam steering including a laser to generate a beam having an optical frequency and an optical phase modulator (OPM) to impart a shift in the optical frequency of the beam from the laser. A dispersive optical element maps the shift in the optical frequency to a corresponding angle with respect to the dispersive optical element, which can comprise a diffraction grating.

Dispersive beam steering based on optical-frequency shift patterns

A coherent imaging system produces coherent flood illumination directed toward a remote object and local oscillator (LO) illumination derived based on a same master oscillator as the flood illumination. A Doppler sensor receives the LO illumination and a return of flood illumination reflected off the object. Doppler shift data from the Doppler sensor, corresponding to a longitudinal velocity of the object relative to the imaging system, is used to produce Doppler-shifted LO illumination received by a low bandwidth, large format focal plane array (FPA), together with the return illumination from the object. Interference between the Doppler-shifted LO illumination and the return illumination facilitates producing an image of the object with the low bandwidth FPA despite the longitudinal velocity. Pixel intensities from the FPA are integrated over a period approaching the maximum interference frequency. The Doppler sensor and FPA may concurrently process return for a high energy laser target spot.

System for coherent imaging in dynamic engagements

Optical signal receivers, systems, and methods of operating the same include a non-line of sight optical signal receiver configured to receive and detect a complex modulated optical signal through a non-line of site propagation path from an optical transmitter, comprising an optical resonator configured to receive the complex modulated optical signal through the non-line of sight propagation path, and to convert the complex modulated optical signal to an intensity modulated signal, and a detector configured to convert the intensity modulated signal into an electrical signal, the electrical signal having an amplitude indicative of an intensity of the intensity modulated signal from the optical resonator, and to provide a detected signal.

Method for non-line-of-sight detection of complex optical signals

A method includes generating, using a transmitter, an optical signal for each fiber incoherently combined in a fiber bundle. The method also includes transmitting the optical signal from each fiber as pulses at a target. The method further includes receiving, using a receiver array, the pulses of the optical signals and identifying one or more parameters of the target based on the pulses of the optical signals.

Fiber-bundled frequency-shifted transmitter for direct detection LIDAR

Methods and systems for generating a high bandwidth linear FM chirp for a laser detection and ranging (LADAR) transceiver is described herein. The LADAR transceiver includes an array of laser sources configured to generate a series of pulses with each pulse offset in frequency by a respective frequency offset from a previous pulse and a subsequent pulse in the series of pulses. A ladder signal can be generated from the series of pulses and modulated with a modulation signal having a modulation bandwidth corresponding to the frequency offset between each pulse to generate the linear chirp signal. The linear chirp signal can have a chirp bandwidth corresponding to the number of laser sources in an array and a modulation bandwidth of the modulation signal.

Linear FM chirp waveform for a LADAR transceiver

Spectral beam combining systems including a multi-element transform optic. In certain examples the multi-element transform optic includes a first cylindrical optical element having positive optical power in a first axis, a second optical element having negative optical power in the first axis, and a third toroidal optical element having positive optical power in the first axis and either positive or negative optical power in a second axis that is orthogonal to the first axis. The first and third optical elements are positioned on opposite sides of the second optical element and equidistant from the second optical element. The multi-element transform optic has an optical path length extending between a front focal plane and a back focal plane that is shorter than an effective focal length of the multi-element transform optic.

Compact transform optics for spectral beam combining

An apparatus includes at least one processor configured to determine a wavefront phase profile of return illumination reflected from a remote object, where the wavefront phase profile is based on interference between Doppler-shifted local oscillator (LO) illumination and the return illumination. The at least one processor is also configured to calculate a wavefront error based on a comparison between (i) the determined wavefront phase profile of the return illumination and (ii) a desired wavefront phase profile of a high energy laser (HEL) beam. The at least one processor is further configured to control a deformable mirror to at least partially compensate the HEL beam for the calculated wavefront error.

Laser beam projection system with dynamic phase compensation

A method includes generating a first optical signal containing doublet pulses. Each doublet pulse includes a first pulse and a second pulse. The second pulses of the doublet pulses are in quadrature with the first pulses of the doublet pulses. The method also includes transmitting the first optical signal towards a target and receiving a second optical signal containing reflected doublet pulses from the target. Each reflected doublet pulse includes a first reflected pulse and a second reflected pulse. The method further includes performing in-phase and quadrature processing of the first and second reflected pulses and identifying one or more parameters of the target based on the in-phase and quadrature processing.

LADAR system supporting doublet waveform for sequential in-phase (I) and quadrature (Q) processing

An apparatus includes a wavefront sensor configured to receive coherent flood illumination that is reflected from a remote object and to estimate wavefront errors associated with the coherent flood illumination. The apparatus also includes a beam director optically coupled to the wavefront sensor and having a telescope and an auto-alignment system. The auto-alignment system is configured to adjust at least one first optical device in order to alter a line-of-sight of the wavefront sensor. The wavefront errors estimated by the wavefront sensor include a wavefront error resulting from the adjustment of the at least one first optical device. The beam director could further include at least one second optical device configured to correct for the wavefront errors. The at least one second optical device could include at least one deformable mirror.

High-performance beam director for high-power laser systems or other systems

Systems and corresponding methods for use in measuring rotation characteristics (e.g., rotation magnitude and direction) of remote targets are provided. A laser light of a known frequency is incident upon the target and reflected. A portion of the reflected laser light is directed to detector field of view, where it is measured and analyzed. The detector field of view is divided into multiple segments, each capable of independently measuring the intensity of laser light incident thereon as a function of time. The linear rotation of the target may be determined from cross-correlation of the light intensity-time response measured at orthogonal pairs of detector halves arranged from combinations of the detector segments. The angular rotation of the target is further determined from this linear rotation.

Target rotation determination by speckle motion characterization

A laser beam projection system builds on a coherent imaging to project a tightly focused laser beam onto a remote object. Coherent flood illumination and local oscillator (LO) illumination are based on one master oscillator. The coherent flood illumination is directed toward a remote object, with a second laser beam directed onto an aimpoint on the same object. A Doppler sensor provides Doppler shift data used to produce Doppler-shifted LO illumination received by a focal plane array, together with the return flood illumination. Interference between the Doppler-shifted LO illumination and the return flood illumination facilitates imaging the object despite the velocity. The wavefront error of the flood illumined remote object image is computed and compared to the desired wavefront of the second laser beam at the aimpoint, with the difference applied to a deformable mirror to shape the second laser beam wavefront for obtaining a desired aimpoint intensity profile.

Described embodiments provide a laser detection and ranging (LADAR) system. The LADAR system transmits a laser signal including a train of coherent pulses and receives a return signal based on the transmitted laser signal that is reflected from a target. The LADAR system forms one or more range bins of the return signal. Each range bin includes a train of coherent pulses formed based upon the transmitted laser signal. For each range bin, the LADAR system generates a phasogram associated with the train of coherent pulses. The phasogram is generated by determining a relative phase between the return signal and a reference signal. The LADAR system generates a vibration spectrum of the return signal based upon the generated phasogram.

Optical phasograms for LADAR vibrometry

A method for removing Doppler ambiguity in a ladar system. The time of each pulse of a sequence of transmitted pulses is offset from that of a uniform sequence of pulses. Each received pulse is represented by a complex number corresponding to its amplitude and phase, and each complex number of the resulting array of complex numbers is multiplied by a complex correction factor having a phase proportional to (i) the time offset of the corresponding pulse, and to (ii) a test frequency of an array of test frequencies, to form a second array of complex numbers. A Fourier transform of the second array is taken, and the value at the test frequency is copied into a corrected spectrum array. The process is repeated for each test frequency in the array of test frequencies, to generate a complete corrected spectrum array.

Non-uniform sampling for unambiguous doppler measurement

Systems and corresponding methods for use in measuring rotation characteristics (e.g., rotation magnitude and direction) of remote targets are provided. A laser light of a known frequency is incident upon the target and reflected. A portion of the reflected laser light is directed to detector field of view, where it is measured and analyzed. The detector field of view is divided into multiple segments, each capable of independently measuring the intensity and frequency of laser light incident thereon. The rotation magnitude of the target may be correlated with the width of the total Doppler spread of reflected light incident upon the detector. The rotation direction of the target may be correlated to a difference in the Doppler spreads measured for corresponding halves of the detector.

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Encino, CA, United States of America

Maurice J Halmos