US Government as Represented by the Secretary of the Army

Neelam Gupta

George J Simonis

Charles Garvin

Ronald G Driggers

Vladislov I Pustovoit

Rachid Dahmani

A system for obtaining spectral images from polarized light comprising a polarization sensitive filter; the polarization sensitive filter being configured to receive light at at least one predetermined polarization orientation; and an achromatic waveplate operatively associated with the polarization sensitive filter; the achromatic waveplate being rotatable; whereby rotation of the achromatic waveplate enables light to enter the polarization sensitive spectral filter at at least two predetermined polarization orientations. A method comprising providing a polarization sensitive filter; the polarization sensitive filter being configured to receive light at at least one predetermined polarization orientation; providing an achromatic waveplate operatively associated with the polarization sensitive filter; the achromatic waveplate being rotatable; whereby rotation of the achromatic waveplate enables light to enter the polarization sensitive spectral filter at the at least two predetermined polarization orientations.

Polarization hyperspectral/multispectral imager and method

A method of detecting oxygen and/or chemical content in a subject, comprising generating at least one spectral image of the subject; generating at least one spectral image of a reference object; comparing spectrum from the subject image to the reference image to thereby reveal the relative oxygen content of the subject. A system for determining the level of oxygenation of the blood of a subject body part comprising: a hyperspectral image generator for generating a plurality of spectral images; an image capture device for capturing the spectral images; a processor for generating hyperspectral image cubes such that the spectrum of the body part is extracted and normalized using the spectrum from the reference object to cancel out the spectral response of the light source and the imager; said processor comparing spectral from a subject image to reference images to thereby reveal the relative oxygen content of the subject.

Noninvasive detection of elements and/or chemicals in biological matter

Embodiments of hyperspectral scene projection/generation systems and methods are disclosed. One method embodiment, among others, comprises dispersing a beam of light at one of a plurality of selectable wavelengths, the beam of light corresponding to a scene, and displaying a spectral image of the scene corresponding to the dispersed beam of light at one of the plurality of selectable wavelengths.

Hyperspectral scene projection/generation systems and methods

A portable acousto-optical (AO) spectrometer system comprised of at least one AO crystal cell device specially designed for cancellation of side-lobe noise at a desired tuned wavelength of operation. Each AO crystal cell device has a transducer attached and forms an AO tunable filter (AOTF) and forms part of a photo-head assembly. The system can include an optical fiber link between the AO spectrometer photo-head assembly and additional features such as an optical alignment coupling attachment that couple an excitation source such as a laser that operates in either pulse or continuous mode, a probing fiber that provides a hand-held member that can emit a source radiation and in turn observe radiation reflected from an observed sample. There are two embodiment of the AO crystal cell device. Either embodiment of the AO crystal cell design can be used in the system, providing a vibration-insensitive AO spectrometer instrument having high sensitivity, accuracy and resolution capabilities. The types of spectroscopic measurements that can be performed using the invention include fluorescence, Raman, absorption and emission.

Portable acousto-optical spectrometers

A spectrometric or photo-detector device accessory for illumination of a sample and highly efficient collection of light therefrom includes an ellipsoidal mirror having focal points f and f ; a first optical fiber leg having a terminus positioned at or near f and containing fibers for conveying light to f and collecting light emitted from a sample positioned at f , a second optical fiber having a terminus positioned at or near f , for collecting light reflected by the mirror and focussed at f and a rigid stand for holding the mirror and fiber optic cables in fixed alignment.

Device for efficient light collection from a sample

GaAs base optical waveguide-based structure for a neural network is discld which may form the basic functional building block of a neural architecture in which the waveguide architecture contains at least three electrically active components which are electrically isolated from each other. The waveguide parameters are such that the laser light propagating through the waveguide is a single-mode in both transverse and lateral directions. A superlattice structure is incorporated in the waveguide core and results in electroabsorption of the input laser light. An electric field is supplied to the active components in order to change the transmission properties of the core material, thus modulating the light passing through the core material.

Optoelectronic waveguide neural architecture

An apparatus for detecting target objects which exhibit ratios of reflectance values that are substantially the same at two separated wavelengths when compared with background objects having reflectance values that are substantially different at the same two wavelengths has a two channel active optical sensor and logic circuitry. A first signal is transmitted at a wavelength lambda-1 which is different from a second signal which is transmitted at a wavelength lambda-2. The two signals are directed towards an object which reflects the signals therefrom. The reflected signals are received and a ratio is calculated. The ratio is compared with a predetermined threshold value to indicate when a target object has been identified.

Growing community of inventors

Bethesda, MD, United States of America

Neelam Gupta