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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.
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By increasing the quantum well barrier width, incorporating spacer layers between the contacts and the multi quantum well region, and optimizing the materials growth parameters, we have dramatically reduced the dark current by many orders of magnitude and thereby significantly increased the detectivity.
Ground-based reception of optical signals from space suffers from degradation of the optical phase-front caused by atmospheric turbulence, leading to a reduction in the effective diameter of the receiving aperture and to random fluctuations of the point spread function in the focal plane.
In this paper, we discuss the development of this very sensitive long wavelength infrared (LWIR) camera based on a Ga/AlGaAs QWIP focal plane array and its performance in quantum efficiency, NETD, uniformity, and operability.
In this paper we discuss the optimization of the detector design, material growth and processing that has culminated in realization of 15 micron cutoff 128 x 128 QWIP focal plane array camera, hand-held and palmize 256 x 256 long-wavelength QWIP cameras and 648 x 480 long-wavelength cameras, holding forth great promise for myriad applications in 6-25 micron wavelength range in science, medicine, defense and industry.
In this paper we discuss the optimization of the detector design, material growth and processing that has culminated in realization of 15 micron cutoff 128x128 QWIP focal plane array camera, hand-held and palmsize 256x256 long wavelength QWIP cameras and 648x480 long-wavelength camera, holding forth great promise for myriad applications in 6-25 micron wavelength range in science, medicine, defense and industry.
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Presentation of the Radiation Hardness Assurance (RHA) guidelines content.
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An apparatus for detecting flashback occurrences in a premixed combustor system having at least one fuel nozzle includes at least one photodetector and at least one fiber optic element coupled between the at least one photodetector and a test region of the combustor system wherein a respective flame of the fuel nozzle is not present under normal operating conditions. A signal processor monitors a signal of the photodetector. The fiber optic element can include at least one optical fiber positioned within a protective tube. The fiber optic element can include two fiber optic elements coupled to the test region. The optical fiber and the protective tube can have lengths sufficient to situate the photodetector outside of an engine compartment. A plurality of fuel nozzles and a plurality of fiber optic elements can be used with the fiber optic elements being coupled to respective fuel nozzles and either to the photodetector or, wherein a plurality of photodetectors are used, to respective ones of the plurality of photodetectors. The signal processor can include a digital signal processor.