C. A. Shott

640/spl times/486 long-wavelength two-color GaAs/AlGaAs quantum well infrared photodetector (QWIP) focal plane array camera

We have designed and fabricated an optimized long-wavelength/very-long wavelength two-color quantum well infrared photodetector (QWIP) device structure. The device structure was grown on a 3-in semi-insulating GaAs substrate by molecular beam epitaxy (MBE). The wafer was processed into several 640/spl times/486 format monolithically integrated 8-9 and 14-15 /spl mu/m two-color (or dual wavelength) QWIP focal plane arrays (FPAs). These FPAs were then hybridized to 640/spl times/486 silicon CMOS readout multiplexers. A thinned (i.e., substrate removed) FPA hybrid was integrated into a liquid helium cooled dewar for electrical and optical characterization and to demonstrate simultaneous two-color imagery. The 8-9 /spl mu/m detectors in the FPA have shown background limited performance (BLIP) at 70 K operating temperature for 300 K background with f/2 cold stop. The 14-15 /spl mu/m detectors of the FPA reaches BLIP at 40 K operating temperature under the same background conditions. In this paper we discuss the performance of this long-wavelength dualband QWIP FPA in terms of quantum efficiency, detectivity, noise equivalent temperature difference (NE/spl Delta/T), uniformity, and operability.

9-/spl mu/m cutoff 256/spl times/256 GaAs/Al/sub x/Ga/sub 1-x/As quantum well infrared photodetector hand-held camera

A 9-/spl mu/m cutoff 256/spl times/256 hand-held quantum well infrared photodetector (QWIP) camera has been demonstrated. Excellent imagery, with a noise equivalent differential temperature (NE/spl Delta/T) of 26 mK has been achieved. In this paper, we discuss the development of this very sensitive long wavelength infrared (LWIR) camera based on a GaAs/AlGaAs QWIP focal plane array and its performance in quantum efficiency, NE/spl Delta/T, minimum resolvable temperature (MRTD), uniformity, and operability.

Long-wavelength 640/spl times/486 GaAs-AlGaAs quantum well infrared photodetector snap-shot camera

A 9-/spl mu/m cutoff 640/spl times/486 snap-shot quantum well infrared photodetector (QWIP) camera has been demonstrated. The performance of this QWIP camera is reported including indoor and outdoor imaging. The noise equivalent differential temperature (NE/spl Delta/T) of 36 mK has been achieved at 300 K background with f/2 optics. This is in good agreement with expected focal plane array sensitivity due to the practical limitations on charge handling capacity of the multiplexer, read noise, bias voltage, and operating temperature.

15-/spl mu/m 128/spl times/128 GaAs/Al/sub x/Ga/sub 1-x/As quantum well infrared photodetector focal plane array camera

In this paper, we discuss the development of very sensitive, very long wavelength infrared GaAs/Al/sub x/Ga/sub 1-x/As quantum well infrared photodetectors (QWIPs) based on bound-to-quasi-bound intersubband transition, fabrication of random reflectors for efficient light coupling, and the demonstration of a 15-/spl mu/m cutoff 128/spl times/128 focal plane array imaging camera. Excellent imagery, with a noise equivalent differential temperature (NE/spl Delta/T) of 30 mK has been achieved.

15-{micro}m 128 x 128 GaAs/Al{sub x}Ga{sub 1{minus}x}As quantum well infrared photodetector focal plane array camera

In this paper, we discuss the development of very sensitive, very long wavelength infrared GaAs/Al/sub x/Ga/sub 1-x/As quantum well infrared photodetectors (QWIPs) based on bound-to-quasi-bound intersubband transition, fabrication of random reflectors for efficient light coupling, and the demonstration of a 15-/spl mu/m cutoff 128/spl times/128 focal plane array imaging camera. Excellent imagery, with a noise equivalent differential temperature (NE/spl Delta/T) of 30 mK has been achieved.

Long-wavelength 256/spl times/256 GaAs/AlGaAs quantum well infrared photodetector (QWIP) palm-size camera

A 9 /spl mu/m cutoff 256/spl times/256 palm-size quantum well infrared photodetector (QWIP) camera weighing only 2.5 lbs, and using 5.5 W of power has been demonstrated. Excellent imagery, with a noise equivalent differential temperature (NE/spl Delta/T) of 23 mK has been achieved. It is well known that QWIP has very low 1/f noise, high operability, and uniformity. As a result, this camera uses a prerecorded nonuniformity correction table (i.e., gains and offsets) stored in its read-only-memory during operation, which enabled the miniaturization of this camera. In this paper, we discuss the development of this very sensitive long-wavelength infrared (LWIR) camera based on a GaAs/AlGaAs QWIP focal plane array (FPA) and its performance in terms of quantum efficiency, NE/spl Delta/T, MRDT, uniformity, and operability.

8-9 and 14-15 meu Two-Color 640x486 GaAs/AlGaAs Quantum Well Infrared Photodetector (QWIP) Focal Plane Array Camera

An optimized long-wavelength two-color quantum well IR photodetector (QWIP) device structure has been designed. This device structure was grown on a three-inch semi- insulating GaAs substrate by molecule beam epitaxy (MBE). This wafer was processed into several 640 X 486 format monolithically integrated 8-9 and 14-15 micrometers two-color QWIP focal plane arrays (FPAs). These FPAs were then hybridized to 640 X 486 silicon CMOS readout multiplexers. A thinned FPA hybrid was integrated into a liquid helium cooled dewar to perform electrical and optical characterization and to demonstrate simultaneous two-color imagery. The 8-9 micrometers detectors in the FPA have shown background limited performance (BLIP) at 70 K operating temperature, at 300 K background with f/2 cold stop. The 14-15 micrometers detectors of the FPA have reached BLIP at 40 K operating temperature at the same background conditions. In this paper we discuss the performance of this long-wavelength dualband QWIP FPA in quantum efficiency, detectivity, noise equivalent temperature difference, uniformity, and operability.

Quantum well infrared photodetector research and development at Jet Propulsion Laboratory

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). 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 palmsize 256 X 256 long-wavelength QWIP cameras and 648 X 480 long-wavelength camera, holding forth great promise for myriad applications in 6 - 25 micron wavelength range in science, medicine, defense and industry. In addition, we present the recent developments in broadband QWIPs, mid-wavelength/long-wavelength dualband QWIPs, long- wavelength/very long-wavelength dualband QWIPs, and high quantum efficiency QWIPs for low background applications in 4 - 26 micrometer wavelength region for NASA and DOD applications.

Long-wavelength 256 x 256 QWIP handheld camera

In this paper, we discuss the development of very sensitive long wavelength infrared GaAs/AlxGa1-xAs quantum well infrared photodetectors (QWIPs), fabrication of random reflectors for efficient light coupling, and the demonstration of first hand-held long-wavelength 256 X 256 QWIP focal plane array camera. Excellent imagery, with a noise equivalent differential temperature of 25 mK has been achieved.

9 mu m cutoff 640x512 pixel GaAs/AlxGa1-xAs quantum well infrared photodetector hand-held camera

A 9 micrometers cutoff 640x512 pixel hand-held quantum well infrared photodetector (QWIP) camera has been demonstrated with excellent imagery. Based on the single pixel test data, a noise equivalent differential temperature (NETD) of 8 mI is expected at 65K operating temperature with f/2 optics at 300K background. This focal plane array has shown background limited performance (BPLI) at 72K operating temperature with the same optics and background conditions. In this paper, we discuss the development of this very sensitive long wavelength infrared (LWIR) camera based on a GaAs/AlGaAs QWIP focal plane array and its performance in quantum efficiency, NETD, uniformity, and operability.