Raytheon Company

Matthew J Klotz

Jean-Paul Bulot

Ian S Robinson

Maurice J Halmos

Timothy P Johnson

Lacy G Cook

David M Filgas

Robert D Stultz

Victor Leyva

Robert J Coda

Juan Carlos Sotelo

N Peter Davis

A LADAR system includes a transmitter configured to emit a directed optical signal. The LADAR system includes an optical aperture through which the directed optical signal is emitted. The optical aperture receives a return optical signal that is based on the directed optical signal. The system includes a detector to generate a measurement by comparing an attribute of the return optical signal to a predefined threshold. The measurement is based on an amount of backscatter in the return optical signal. The system includes an obstructive element that is controllable, based on the measurement, to move either into or out of a path of the return optical signal. The obstructive element is configured to block the return optical signal at least partly. The system includes a focal plane located in the path of the return optical signal. The obstructive element is disposed between the optical aperture and the focal plane.

Optical system that detects and blocks backscatter

A LADAR system includes a transmitter configured to emit a directed optical signal. The LADAR system includes a shared optical aperture through which the directed optical signal is emitted. The shared optical aperture includes a first pupil plane. The shared optical aperture receives a return optical signal that is based on the directed optical signal. The system includes a mirror with a hole through which the directed optical signal passes. The mirror also reflects the return optical signal towards an imager. The imager receives the return optical signal and generates an image. The image is based on a portion of the return optical signal. The system also includes a partial aperture obscuration at a second pupil plane. The partial aperture obscuration may block a portion of internal backscatter in the return optical signal. The system also includes a focal plane to record the image.

Optical system to reduce local internal backscatter

A laser system comprises a pump diode, fiber, relay optics, and a microchip laser crystal. The pump diode produces light at a first wavelength. The fiber receives the light from the pump diode and produces a round, homogeneous light spot at an output of the fiber. The relay optics receives the light from the fiber. The microchip laser crystal receives the light from the relay optics and produces a linearly polarized single frequency output at a second wavelength. The microchip laser crystal includes a first layer and a second layer. The first layer absorbs the light at the first wavelength and emits light at the second wavelength. The second layer receives the light at the second wavelength and either provides a polarization dependent loss at the second wavelength or maintains a polarization of the light at the second wavelength.

Laser system and method for producing a linearly polarized single frequency output using polarized and non-polarized pump diodes

In one aspect, a method includes forming range bins from range compressed data, the range compressed data comprising a train of coherent pulses formed based on a transmitted signal from a laser detection and ranging (LADAR) sensor and having a large time-bandwidth product and for each range bin, compensating for motion of the LADAR sensor, performing a Fourier transform on the compressed range data, determining a centroid of individual velocity measurements and performing Fourier transform of the centroid to determine a vibration.

Range-resolved vibration using large time-bandwidth product LADAR waveforms

In accordance with various aspects of the disclosure, a method, an apparatus and a system for characterizing and compensating for deterministic phase nonlinearities and distortion inherent in radio frequency and optical components utilized to synthesize a single sideband suppressed carrier optical waveform in the presence of random phase noise generated by an optical carrier source is disclosed. The method comprises mixing a modulated optical signal with a continuous wave optical signal in an optical coupler; optically heterodyning the mixed signal output from the optical coupler in a detector to produce a radio frequency waveform; and analyzing the produced radio frequency waveform in a processor based on a phase history of a preselected continuous wave signal to measure distortion characteristics of the radio frequency modulated optical signal.

Method and apparatus for synthesizing and correcting phase distortions in ultra-wide bandwidth optical waveforms

In one aspect, a method includes representing a range of Doppler frequency offsets as a local oscillator waveform comprising a plurality of digital waveform samples, selecting a portion of the plurality of digital waveform samples using a Doppler value to form an optical heterodyne; and generating a signal associated with a target within a bandwidth of a receiver using the optical heterodyne.

Doppler compensation for a coherent LADAR

In accordance with various aspects of the disclosure, a method and apparatus is disclosed for increasing waveform bandwidth of an optical frequency waveform during optical double sideband suppressed carrier modulation. An optical modulator is configured to operate in double sideband, suppressed carrier modulation (DSB-SC) mode producing multiple optical sidebands and optical sideband harmonics. Proper selection of the appropriate optical harmonic via optical filter enables the synthesis of ultra-wideband single-sideband, suppressed carrier (SSB-SC) optical waveforms while simultaneously simplifying the radio frequency (RF) circuitry that generates the modulating radio frequency waveform.

Method and apparatus for synthesizing ultra-wide bandwidth waveforms

A ladar system with phase correction. The novel ladar system includes optics for receiving a first signal that is a reflected version of a transmitted laser signal, an optical delay line for providing a second signal that is a delayed version of the transmitted laser signal, and a mechanism for mixing the first signal with the second signal. The second signal is delayed by a time Tthat reduces a relative time difference between the first and second signals such that phase errors caused by laser transmitter instabilities and nonlinear modulation are less than a predetermined level.

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Pasadena, CA, United States of America

Matthew J Klotz