US Government As Represented by the Secretary of the Army

Other

The State University of New York

Maxion Technologies, Inc.

The University of Texas System

The Walter Reed Army Institute of Research

Gregory L Belenky

Thomas J Balkin

Helen C Sing

Daniel P Redmond

Gary H Kamimori

Stanley W Hall

Maria L Thomas

David R Thorne

Nancy Jo Wesensten

Serge Luryi

Leon Shterengas

Sergey Suchalkin

Mitra Dutta

Michael A Stroscio

John D Bruno

Richard L Tober

Mikhail V Kisin

Mikhail Kisin

Mikhail A Belkin

Arthur David Westerfeld

Nacy Jo Wesensten

David Westerfeld

An LED optimized for use in low-cost gas or other non-solid substance detection systems, emitting two wavelengths ('colors') of electromagnetic radiation from the same aperture is disclosed. The LED device emits a light with a wavelength centered on an absorption line of the target detection non-solid substance, and also emits a reference line with a wavelength that is not absorbed by a target non-solid substance, while both wavelengths are transmitted through the atmosphere with low loss. Since the absorption and reference wavelengths are emitted from the same exact aperture, both wavelengths can share the same optical path, reducing the size and cost of the detector while also reducing potential sources of error due to optical path variation.

Bi-directional dual-color light emitting device and systems for use thereof

A method of fabrication of barrier diode based infrared detectors, utilizing the growth of unstrained, not relaxed III-V compound semiconductor material layers having a lattice constant over 6 Angstrom, is provided. The growth is performed by the means of Molecular Beam Epitaxy (MBE) or Metal-Organic Vapor Phase Epitaxy (MOVPE). The method comprises the use of bulk crystalline substrates and the growth of a transitional layer of GaInAsSb with graded composition, followed by an optional thick layer of GaInAsSb of constant composition, lattice matched to the said III-V compound semiconductor material layers, the said optional layer of GaInAsSb of constant composition serving as a virtual substrate. The method provides high crystalline quality layers suitable for semiconductor device fabrication that can effectively interact with electromagnetic radiation of the mid-infrared spectral range with a wavelength between about 2 micrometers to about 16 micrometers.

Compound semiconductor device on virtual substrate

The present invention provides a QCL device with an electrically controlled refractive index through the Stark effect. By changing the electric field in the active area, the energy spacing between the lasing energy levels may be changed and, hence, the effective refractive index in the spectral region near the laser wavelength may be controlled.

Quantum cascade lasers with electrically tunable emission wavelengths

A semiconductor light source comprises a substrate, lower and upper claddings, a waveguide region with imbedded active area, and electrical contacts to provide voltage necessary for the wavelength tuning. The active region includes single or several heterojunction periods sandwiched between charge accumulation layers. Each of the active region periods comprises higher and lower affinity semiconductor layers with type-II band alignment. The charge carrier accumulation in the charge accumulation layers results in electric field build-up and leads to the formation of generally triangular electron and hole potential wells in the higher and lower affinity layers. Nonequillibrium carriers can be created in the active region by means of electrical injection or optical pumping. The ground state energy in the triangular wells and the radiation wavelength can be tuned by changing the voltage drop across the active region.

Semiconductor light source with electrically tunable emission wavelength

An apparatus and a method for predicting cognitive performance of an individual based on factors including preferably sleep history and the time of day. The method facilitates the creation of predicted cognitive performance curves that allow an individual to set his/her sleep times to produce higher levels of cognitive performance. The method also facilitates the reconstruction of past cognitive performance levels based on sleep history.

Method and system for predicting human cognitive performance

Intersubband semiconductor lasers (ISLs) are of great interest for mid-infrared (2-20 &#x3bc;m) device applications. These semiconductor devices have a wide range of applications from pollution detection and industrial monitoring to military functions. ISLs have generally encountered several problems which include slow intrawell intersubband relaxation times due to the large momentum transfer and small wave-function overlap of the initial and final electron states in interwell transitions. Overall, the ISL's of the prior art are subject to weak intersubband population inversion. The semiconductor device of the present invention provides optimal intersubband population inversion by providing a double quantum well active region in the semiconductor device. This region allows for small momentum transfer in the intersubband electron-phonon resonance with the substantial wave-function overlap characteristic of the intersubband scattering.

Intersubband semiconductor lasers with enhanced subband depopulation rate

A system and a method for providing a determination of predicted cognitive performance of an individual preferably based on the time of day and on factors including sleep history based on activity data from an actigraph. The system and the method provide a numerical representation of the predicted cognitive performance. Both may be used to optimize the work schedule of the actigraph wearer to maximize the cognitive capacity during working hours.

Method and system for predicting human cognitive performance using data from an actigraph

An apparatus and method for predicting cognitive performance of an individual based on factors including preferably sleep history and the time of day. The method facilitates the creation of predicted cognitive performance curves that allow an individual to set his/her sleep times to produce higher levels of cognitive performance. The method also facilitates the reconstruction of past cognitive performance levels based on sleep history.

Method and system for predicting human congnitive performance

An apparatus and method for predicting cognitive performance of an individual based on factors including sleep history and the time of day. The method facilitates the creation of predicted cognitive performance curves that allow an individual to set his/her sleep times to produce higher levels of cognitive performance. The method also facilitates the reconstruction of past cognitive performance levels based on sleep history.

An apparatus and method for predicting cognitive performance of an individual based on factors including preferably sleep history, the time of day, and the individual's activities. The method facilitates the creation of predicted cognitive performance curves that allow an individual to set his/her sleep times to produce higher levels of cognitive performance. The method also facilitates the reconstruction of past cognitive performance levels based on sleep history.

A system and a method for providing a determination of predicted cognitive performance of an individual preferably based the time of day and on factors including sleep history based on activity data from an actigraph and the individual's activities. The system and the method provide a numerical representation of the predicted cognitive performance. Both may be used to optimize the work schedule of the actigraph wearer to maximize the cognitive capacity during working hours.

System and method for predicting human cognitive performance using data from an actigraph

Method for predicting human cognitive performance

A system and a method for providing a determination of predicted cognitive performance of an individual based the time of day and on factors including sleep history based on activity data from an actigraph. The system and the method provide a numerical representation of the predicted cognitive performance. Both may be used to optimize the work schedule of the actigraph wearer to maximize the cognitive capacity during working hours.

Growing community of inventors

Kensington, MD, United States of America

Gregory L Belenky