SEARCH · Search NASA
Results for “focal planes”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Curved focal plane arrays
Explore the source record for details and available documents.
Quantum Well Infrared Photodetector Focal Plane Arrays for Astronomy
Explore the source record for details and available documents.
Operating parameter optimization of single color and four-color spatially separated QWIP focal plane array
Explore the source record for details and available documents.
Large Format Quantum Well Infrared Photodetector Focal Plane Arrays for Astronomical Instrumentations
Quantum Well Infrared Photodetectors (QWIPs) afford greater flexibility than the usual extrinsically doped semiconductor IR detectors.
Commercialization of Quantum Well Infrared Photodetector QWIP Focal Plane Arrays
Many commercial and government applications need high performance, large format, long-wavelength infrared (LWIR) detector arrays in the range of 6-20 mu.
Quantum Well Infrared Photodetector (QWIP) Focal Plane Arrays
Intrinsic infrared detectors in the long-wavelength range (6 - 20 ??are based on interband transition which promotes an electron across the band gap (E(sub g)) from the valence band to the conduction band.
Long-wavelength 640x484 GaAs/Al x Ga 1-x As Quantum Well Infrared Photodetector Focal Plane Array Camera
A hand-held quantum well infrared photodetector camera has been demonstrated.
A Method Using Focal Plane Analysis to Determine the Performance of Reflector Antennas
Reflector antenna optimization schemes using array feeds and deformable flat plates (DFP) have been used to design systems that recover antenna losses resulting from antenna distortions.
640x486 Long-Wavelength Two-Color GaAs/AlGaAs Quantum Well Infrared Photodetector (QWIP) Focal Plane Array Camera
An optimized long-wavelength very long-wavelength two-color Quantum Well Infrared Photodetector (QWIP) device structure has been designed.
Recent Developments and Applications of Quantum Well Infrared Photodetector Focal Plane Arrays
One of the simplest device realizations of the classic particle-in-the-box problem of basic quantum mechanics is the Quantum Well Infrared Photodetector (QWIP).
Operating parameter optimization of single color and four-color spatially separated QWIP focal plane array
This paper will report on the characterization of spatially separated four-color QWIP FPA and LWIR QWIP camera. Optimization of operating parameters for each color and the best optimized operating parameters for all four-color operating simultaneously will be discussed.
640x486 Long-wavelength Dualband GaAs/AlGaAs Quantum Well Infrared Photodetector (QWIP) Focal Plane Array Camera
An optimized long-wavelength/very long-wavelength two-color Quantum Well Infrared Photodetector (QWIP) device structure has been designed. This device structure was grown on a three-inch semi-insulating GaAs substrate by molecular beam epitaxy (MBE).
10-16 meu broadband 640X512 GaAs/AlGaAs quantum well infrared photodetector (QWIP) focal plane array
In this presentation, we will discuss the development of this large format broadband infrared FPA based on a GaAs/AlGaAs materials system and its performance in quantum efficiency, uniformity, and operability.
Thermal Imaging with Novel Infrared Focal Plane Arrays and Quantitative Analysis of Thermal Imagery
We have developed a single long-wavelength infrared (LWIR) quantum well infrared photodetector (QWIP) camera for thermography. This camera has been used to measure the temperature profile of patients. A pixel coregistered simultaneously reading mid-wavelength infrared (MWIR)/LWIR dual-band QWIP camera was developed to improve the accuracy of temperature measurements especially with objects with unknown emissivity. Even the dualband measurement can provide inaccurate results due to the fact that emissivity is a function of wavelength. Thus we have been developing a four-band QWIP camera for accurate temperature measurement of remote object.
Large format long-wavelength infrared narrow-band, multi-band, and broad-band QWIP focal plane arrays
A 640x512 pixel, long-wavelength cutoff, narrow-band quantum well infrared photodetector focal pllay array, a four-band QWIP FPA in 4-16 um spectral region, and a broad-band QWIP FPA having 15.4 mum cutoff have been demonstrated. In this paper we discuss the detector designs, dark currents, quantum efficiencies, responsivities, detectivities, noise equivalent differential temperatures, the effect of FPA nonuniformity on performance, and the operabilities of these QWIP FPAs.
Matching a curved focal plane with CCD's - Wide field imaging of glancing incidence X-ray telescopes
The design of a wide field imaging camera suitable for use with a glancing incidence X-ray telescope is complicated by the sharply concave nature of the optimum focal surface of such a telescope. Such a camera made up of a mosaic of CCDs is being designed which is intended for flight aboard the Advanced X-ray Astrophysics Facility (AXAF). The design rationale and tradeoffs are discussed, and the layout for the imaging CCD array is presented. The related issue of optimizing performance of transmission objective gratings is also discussed, and the array of CCD orientations suitable for this problem is presented.
A method using focal plane analysis to determine the performance of reflector antennas
Reflector antenna optimization schemes using array feeds have been used to recover antenna losses resulting from antenna distortions and aberrations and to generate contour coverage patterns. Historically, these optimizations have been carried out using the antenna far-field scattered patterns. The far-field patterns must be calculated separately for each of the array feed elements. For large or complex antennas (which include beam-waveguide antennas), the far-field calculation times can be prohibitive. This article presents a method with which the optimization can be carried out in the antenna focal region, where the scattering calculation needs only to be done once independently of the number of the elements in the array. This article also includes the results of a study, utilizing this unique technique, to determine the capabilities and limitations of using array feeds to compensate for gravitational induced losses in large reflector antennas.