United States of America As Represented by the Secretary of the Air Force

Other

Christian Keyser

Chad M Welsh

Trevor Courtney

John Philip Timler

Richard Kenneth Martin

Luke A Ausley

David M Barrett

A cylindrical electrode module of a fiber optic laser system includes an inner cylinder having an inner repeating pattern of longitudinally-aligned positive and negative electrodes on an outer surface of the inner cylinder. The cylindrical electrode mode includes an outer cylinder that encloses the inner cylinder. The outer cylinder that has an outer repeating pattern of longitudinally-aligned negative and positive electrodes on an inner surface of the inner cylinder that are in corresponding and complementary, parallel alignment with the positive and negative electrodes of the inner repeating pattern on the outer surface of the inner cylinder. The cylindrical electrode module includes an optical fiber having an input end configured to align with and be optically coupled to a pump laser. The optical fiber is wrapped around the inner cylinder within the outer cylinder to form a cylindrical fiber assembly. The electrodes are activated to achieve quasi-phase matching.

Wavelength flexibility through variable-period poling of a compact cylindrical optical fiber assembly

Systems and methods for three-dimensional (3-D) imaging enabled by natural range-dependent processes. Multiple lasers are configured to independently flash illuminate a target object to 3-D image a resultant 'scene' onto a focal plane array (FPA). The first laser produces a wavelength non-resonant with an atmospheric absorption line along the illumination path. The second laser produces a wavelength resonant with the atmospheric absorption line, and closely spaced with the non-resonant wavelength. A ratio of the respective intensities recorded at the FPA for the two wavelengths calculates a range to the target object.

Range-enabled three-dimensional imaging system and associated methods

A fiber laser system includes a high power pump laser, an optical fiber that is aligned to receive output from the high power pump laser. The fiber laser system includes a first pair of orthogonally opposed, periodic electrode structures longitudinally aligned on opposite first and second sides of the optical fiber. The fiber laser system includes a controller that is communicatively coupled to the first pair of periodic electrode structures. The controller performs variable period poling of the first pair of periodic electrode structures to achieve quasi-phase matching (QPM).

Wavelength flexibility through variable-period poling of optical fiber

A cylindrical electrode module of a fiber optic laser system includes an inner cylinder having an inner repeating pattern of longitudinally-aligned positive and negative electrodes on an outer surface of the inner cylinder. The cylindrical electrode mode includes an outer cylinder that encloses the inner cylinder. The outer cylinder that has an outer repeating pattern of longitudinally-aligned negative and positive electrodes on an inner surface of the inner cylinder that are in corresponding and complementary, parallel alignment with the positive and negative electrodes of the inner repeating pattern on the outer surface of the inner cylinder. The cylindrical electrode module includes an optical fiber having an input end configured to align with and be optically coupled to a high power pump laser. The optical fiber is wrapped around the inner cylinder within the outer cylinder to form a cylindrical fiber assembly. The electrodes are activated to achieve quasi-phase matching.

A LADAR having a transmitter and a receiver. The transmitter includes a laser for delivering an original beam pulse having a time duration. A nonlinear element receives the original beam pulse and outputs a multispectral incident beam pulse. For each wavelength component of the incident beam pulse, a unique wavelength-dependent variation of intensity is imparted over the time duration of the incident beam pulse. This creates a unique waveform shape for each component. Output optics direct the incident beam pulse onto a target, which reflects from the target as a scattered beam pulse. The receiver includes a single-pixel sensor for receiving the scattered beam pulse and measuring and outputting an intensity of the scattered beam pulse over time, which creates a scattered beam pulse envelope. A processor receives the scattered beam pulse envelope, applies factors to fit the waveform shapes to the scattered beam pulse envelope, and derives a reflectivity of the target for each of the wavelength components from the factors.

Multispectral LADAR using wavelength shaping

A LADAR that includes a transmitter and a receiver. The transmitter includes a laser for delivering an original beam pulse. A nonlinear optic receives the original beam pulse and outputs wavelengths as an incident beam pulse. Output optics direct the incident beam pulse onto a target, which reflect from the target as a reflected beam pulse. The receiver includes a dispersive optic for temporally dispersing the wavelengths in the reflected beam pulse, thereby producing a dispersed beam pulse. A single-pixel sensor receives the dispersed beam pulse, and measures and outputs a separate intensity value for each of the wavelengths in the dispersed beam pulse based at least in part on the temporal dispersion of the wavelengths. A processor receives the intensity values from the dispersed beam pulse, correlates the intensity values with the wavelengths, compares the intensity values to known intensity values from the incident beam pulse, produces ratio values for each of the wavelengths, and produces reflectance data in regard to the target from the ratio values.

Multispectral LADAR using temporal dispersion

In a polarimeter, a polarization modulator changes a polarization phase of an output optical pulse with a modulation function that varies in time over the duration of the optical pulse. A static polarization state analyzer, which includes a one or more static polarization component analyzers and detectors, receives the modulated optical pulse after interaction with a target medium and provides time varying intensities of the polarization components of the received pulse. A signal processing module determines a polarization property of the target medium, such as a Mueller matrix, dependent upon time varied intensities over the duration of the received optical pulse. A time-division optical multiplexer may be used to combine the outputs from multiple static polarization component analyzers to form a single time-multiplexed signal comprising a plurality of optical pulses that are separated in time and passed to a single photo-detector.

Temporally multiplexed LADAR polarimeter

An optical system including a laser system for generating a plurality of coaxial laser beams. The laser beams are combined by the laser system for generating at least two different frequency components. One or more hollow core photonic crystal fibers each filled with a noble gas receive the coaxial laser beams from the laser system and generate an idler emission having an idler frequency component according to four-wave mixing of the at least two different frequency components in the one or more hollow core photonic crystal fibers. A control system is configured to control a gas pressure of the one or more hollow core photonic crystal fibers for controlling the idler frequency component of the idler emission.

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Shalimar, FL, United States of America

Christian Keyser