Keyword: Spectroscopy

Briefs: Photonics/Optics

An ultraviolet light source that comprises a tunable diode laser and associated optics provides the optical excitation needed for simultaneous wavelength-modulation-absorption...

Briefs: Photonics/Optics
Fourier-Transform X-Ray Microscope

A proposed x-ray instrument - a Fourier-transform x-ray microscope - would enable high-resolution imaging of objects with sizes of the order of 20 nm. (This size range is typical of cell organelles.) The instrument would also offer a spectroscopic capability for the sensitive detection and identification of...

Briefs: Motion Control

A double-parallelogram ("porch swing") carriage mechanism has been devised to provide for free linear motion of one or more retroreflector(s) in a Fourier-transform infrared...

Briefs: Photonics/Optics

An apparatus that includes a pulsed electron gun and a high-resolution ultraviolet spectrometer has been developed for use in (1) pulsed electron-impact excitation of transitions...

Briefs: Photonics/Optics

Several high-fidelity imaging spectrometers have been designed with convex diffraction gratings for wavelengths ranging from the ultraviolet to the thermal infrared. All the designs...

Briefs: Test & Measurement
A Mass-Spectrometer System for Detecting Gas Leaks

The Hydrogen Umbilical Mass Spectrometer (HUMS) consists of an integrated sample delivery system, a commercial mass-spectrometer-based gas analyzer, and a set of calibration gas mixtures traceable to NIST (National Institute for Standards and Technology). The system, except for the calibration...

Briefs: Photonics/Optics

Miniature high-resolution optical-absorption sensors for detecting trace amounts of chemical species of interest in gas and liquid samples are undergoing development. The transducer in...

Briefs: Photonics/Optics

A proposed optoelectronic apparatus would perform the combined functions of a confocal microscope and a Raman spectrometer. It would be used to acquire Raman-spectral-image and/or...

Briefs: Photonics/Optics

A method of designing a compact pushbroom imaging spectrometer includes explicit consideration and minimization of nonuniformity of spatial and spectral response. It appears that...

Briefs: Photonics/Optics

A spectrometer has been developed for acquiring transient emission and absorption spectra in the wavelength range from 1.2 to 5.0 µm. It could be used to characterize flames, turbulence, and other transient...

Briefs: Physical Sciences
Dislocation-Induced Changes in InxGa1 -xAs Quantum Dots

A report describes an experimental investigation that revealed a previously unknown type of spatial alignment of quantum dots (QDs) in InxGa1 -xAs/GaAs multilayer structures. Multilayer arrays of QDs (in the form of nanometer-sized...

Briefs: Physical Sciences
Thermodynamic Instability of InxGa1–xAs/GaAs Quantum Dots

A report describes experiments that generated evidence of thermodynamic instability of nanometer-size islands (quantum dots) in InxGa1–xAs grown on GaAs. InxGa1–xAs/GaAs specimens were grown by metal-organic chemical vapor deposition,...

Briefs: Physical Sciences

A computer-controlled instrumentation system has been developed for use in measuring concentrations of various atomic species in the exhaust gases of a space-shuttle main engine on a...

Briefs: Materials

An improved method of accelerated testing reduces the time needed to analyze the abilities of zinc-rich primers to protect steel substrates against corrosion in a seacoast...

Briefs: Photonics/Optics

A complementary metal oxide/semiconductor (CMOS) focal-plane readout circuit for an imaging array of long-wavelength infrared (LWIR) photodetectors effects in-pixel current-mode...

Briefs: Electronics & Computers
Acousto-Optic Tunable Filter Spectrometers

Spectrometers are used for applications such as chemical analysis, remote sensing, environmental measuring, and optical measurements. Most spectrometers utilize prisms and gratings, where the dispersion of light depends upon the angle and rotation of the grating. But gratings and other moving parts are...

Briefs: Physical Sciences
Ion-Mobility Spectrometric Determination of Hydrazines

Hydrazine, monomethylhydrazine, and unsymmetrical dimethylhydrazine can be detected and measured at concentrations as low as 10 parts per billion in the presence of ammonia at concentrations as high as 10 parts per million (greater than the odor threshold concentration of ammonia,...

Briefs: Photonics/Optics

A spectrometer/radiometer now undergoing development is designed to be used aboard a spacecraft to measure the heights of cloud tops on Earth. The spectrometer/radiometer performs...

Briefs: Photonics/Optics

The figure shows a first-phase prototype of a miniature, rugged long-wavelength infrared (LWIR) spectrometer that incorporates recent advances in the design and fabrication of microelectronic and...

Briefs: Physical Sciences

An improved array of microcalorimeters has been devised for use as photon detectors in an x-ray spectrometer for astrophysical research. The spectrometer will be used to measure the spectra of...

Briefs: Electronics & Computers

Basic research on ion-trap mass spectrometry (IT/MS) in the Environmental Molecular Sciences Laboratory (EMSL) at Pacific Northwest National Laboratory has resulted in a...

Briefs: Materials
Properties of Cubic Boron Nitride Films

A report describes an experimental study of the surface-chemical, microstructural, and tribological properties of cubic boron nitride (c-BN) films, which are potentially useful as hard, wear-resistant coatings on bearings and on steel-cutting tools. For the experiments, BN films about 500 nm thick were...

Briefs: Physical Sciences

Scanning filters based on surface plasmons would be used as the adjustable wavelength-selective (band-pass) devices in a class of proposed miniature spectrometers. These filters...

Briefs: Physical Sciences

A robust sensor based on the electrochemical oxidation of methanol has been developed for use in measuring the concentration of methanol dissolved in water. The sensor is expected to...

Briefs: Electronics & Computers
Snapshot CCD Camera With Microelectromechanical Shutter

A proposed charge-coupled-device (CCD) camera would be mechanically shuttered by a planar array of micromachined, electromechanically actuated shutters. This proposal has arisen as part of the solution to the problem of designing a visible/near-infrared imaging spectrometer using a...

Briefs: Photonics/Optics

An important nondestructive evaluation (NDE) measurement technique is to record the vibration-mode spectrum of a material part or structure, excited by a random or...

Briefs: Photonics/Optics

A vapor drying treatment removes traces of water and other contaminant residues that remain on the surface of a patterned semiconductor substrate after chemical cleaning in...

Briefs: Physical Sciences

An imaging spectroscopic technique is undergoing development for use in remote detection of ice and mapping of the thickness of ice on aircraft surfaces. The technique is based on the...

Briefs: Robotics, Automation & Control

Zinc telluride is a semiconductive material that has been found to become photorefractive when it is suitably doped with vanadium or with manganese and vanadium. The combination of...