排序方式: 共有4条查询结果,搜索用时 125 毫秒
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S. D. Gunapala S. V. Bandara J. K. Liu S. B. Rafol J. M. Mumolo C. A. Shott R. Jones J. Woolaway II J. M. Fastenau A. K. Liu M. Jhabvala K. K. Choi 《Infrared Physics & Technology》2003,44(5-6):411-425
A 9 μm cutoff 640 × 512 pixel hand-held quantum well infrared photodetector (QWIP) camera has been demonstrated with excellent imagery. A noise equivalent differential temperature (NEDT) of 10.6 mK is expected at a 65 K operating temperature with f/2 optics at a 300 K background. This focal plane array has shown background limited performance at a 72 K operating temperature with the same optics and background conditions. In this paper, we discuss the development of this very sensitive long-wavelength infrared camera based on a GaAs/AlGaAs QWIP focal plane array and its performance in quantum efficiency, NEDT, uniformity, and operability. In the second section of this paper, we discuss the first demonstration of a monolithic spatially separated four-band 640 × 512 pixel QWIP focal plane array and its performance. The four spectral bands cover 4–5.5, 8.5–10, 10–12, and 13.5–15 μm spectral regions with 640 × 128 pixels in each band. In the last section, we discuss the array performance of a 640 × 512 pixel broad-band (10–16 μm full-width at half-maximum) QWIP focal plane. 相似文献
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A modulation doped thyristor concept is described for LWIR photodetection based upon intersubband bound to continuum absorption. The intersubband absorption generates photocurrent from undoped quantum wells to modulation doped layers (MDL). Due to the lower dark current compared to conventional quantum well infrared photodetectors (QWIPs), the thyristor infrared detector operates with little or no cooling and with similar or better performance than QWIPs at low temperatures. The operating characteristics of absorption coefficient, quantum efficiency, responsivity, detectivity, infrared gain, and dark current are determined as a function of thyristor voltage and input power level in the range of 1 μW/cm2. 相似文献
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A. Rogalski 《Opto-Electronics Review》2006,14(1):84-98
Hitherto, two families of multielement infrared (IR) detectors are used for principal military and civilian infrared applications;
one is used for scanning systems (first generation) and the other is used for staring systems (second generation). Third generation
systems are being developed nowadays. In the common understanding, third generation IR systems provide enhanced capabilities
like larger number of pixels, higher frame rates, better thermal resolution as well as multicolour functionality and other
on-chip functions.
In the paper, issues associated with the development and exploitation of materials used in fabrication of third generation
infrared photon detectors are discussed. In this class of detectors two main competitors, HgCdTe photodiodes and quantum well
IR photoconductors (QWIPs) are considered. The performance figures of merit of state-of-the-art HgCdTe and QWIP focal plane
arrays (FPAs) are similar because the main limitations come from the readout circuits. However, the metallurgical issues of
the epitaxial layers such as uniformity and number of defected elements are the serious problems in the case of long wavelength
infrared (LWIR) and very LWIR (VLWIR) HgCdTe FPAs. It is predicted that superlattice based InAs/GaInSb system grown on GaSb
substrate seems to be an attractive to HgCdTe with good spatial uniformity and an ability to span cutoff wavelength from 3
to 25 μm. 相似文献
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