Long wavelength infrared 128*128 Al/sub x/Ga/sub 1-x/As/GaAs quantum well infrared camera and imaging system

Bethea, G.C.; Levine, B. F.; Asom, M. T.; Leibenguth, R. E.; Stayt, J. W.; Glogovsky, K.G.; Morgan, Robert; Blackwell, John D.; Parrish, William J.

doi:10.1109/16.239734

Cited by 61 publications

(14 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, this difficulty can easily overcome by fabricating light coupling structures such as gratings or randomly roughened reflectors on top of each detector pixels. Although random reflectors [4] have achieved relatively high quantum efficiencies with large test device structures, it is difficult to fabricate random reflectors for shorter wavelength detectors relative to very long-wavelength detectors (i.e., 15 µm), because the feature sizes of random reflectors are linearly proportional to the peak wavelength of the detectors [10]. For example, the minimum feature sizes of the random reflectors for 15 µm cutoff and 9 µm cutoff FPAs were 1.25 and 0.6 µm, respectively.…”

Section: X512 Pixel Narrow-band Focal Plane Arraymentioning

confidence: 99%

“…There has been much interest lately [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] in large format QWIP focal plane arrays (FPAs). In this paper we discuss the design, fabrication, and test results of a 640x512 pixel narrow-band QWIP FPA.…”

Section: Introductionmentioning

confidence: 99%

“…The idea of using multi-quantum-well (MQW) structures to detect infrared radiation (i.e., QWIP) can be explained by using the basic principles of quantum mechanics. The design and optimization of MQW based infrared detectors are described in detail elsewhere [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Large format long-wavelength infrared narrow-band, multi-band, and broad-band QWIP focal plane arrays

et al. 2004

View full text Add to dashboard Cite

A 640x512 pixel, long-wavelength cutoff, narrow-band (∆λ/λ~10%) quantum well infrared photodetector (QWIP) focal plane array (FPA), a four-band QWIP FPA in 4-16 µm spectral region, and a broad-band (∆λ/λ~42%) QWIP FPA having 15.4 µm cutoff have been demonstrated. In this paper we discuss the detector designs, dark currents, quantum efficiencies, responsivities, detectivities, noise equivalent differential temperatures (NEDTs), the effect of FPA nonuniformity on performance, and the operabilities of these QWIP FPAs. In addition, we discuss the development of a very sensitive (NEDT~10.6 mK) 640x512 pixel thermal imaging camera having 9 µm cutoff.Index Terms: Infrared, long-wavelength infrared, mid-wavelength infrared, narrow-band infrared, multi-band infrared, broad-band infrared, infrared imaging camera, focal plane array, quantum well infrared photodetectors.

show abstract

Section: X512 Pixel Narrow-band Focal Plane Arraymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Large format long-wavelength infrared narrow-band, multi-band, and broad-band QWIP focal plane arrays

et al. 2004

View full text Add to dashboard Cite

show abstract

“…As mentioned earlier this higher dark current is due to thermionic emission and thus causes the charge storage capacitors of the readout circuitry to saturate. Since the QWIP is a high impedance device, it should yield a very high charge injection coupling efficiency into the integration capacitor of the multiplexer [10].…”

Section: Broadband Qwipmentioning

confidence: 99%

Large-format broadband multicolor GaAs/AlGaAs quantum well infrared photodetector (QWIP) focal plane arrays

Bandara

Gunapala

Liu

et al. 2001

Materials for Infrared Detectors

View full text Add to dashboard Cite

The GaAs/A1GaAs based Quantum Well Infrared Photodetectors (QWIPs) afford greater flexibility than the usual extrinsically doped semiconductor JR detectors because the wavelength of the peak response and cutoff can be continuously tailored over any wavelength between 6-20 jim. The spectral band width of these detectors can be tuned from narrow (AX/A -10 %) to wide (AX/X -50 %) allowing various applications. Also, QWIP offers multi-color infrared cameras which is capable of simultaneously acquiring images in different infrared bands. Each pixel of such array consists of vertically stacked, independently readable, QWIP detectors sensitive in different narrow (AX 1 rim) infrared bands. In this article, we discuss the results of a 10-16 jtm large format broadband QWIP focal plane array (EPA). The size of the FPA is 640x512 and its pixel pitch is 25 microns. The highest operating temperature of the FPA is 45K, and it was determined by the charge storage capacity and the other features of the particular readout multiplexer used in this demonstration. Excellent imagery, with a noise equivalent differential temperature (NEAT) of 55mK has been achieved. In addition, we will discuss the developments and results of the 640x5 12 dual-band QWIP EPA.

show abstract

“…Today's state-of-the-art systems consist of arrays with thousands of QWIPs which can detect thermal images at high resolution and with a low background limited infrared performance temperature. 1,2 The detectors used in these systems are optimized for high sensitivity and function usually at cryogenic temperatures. Recently, new applications such as high speed modulators and detectors based on intersubband transitions have been proposed.…”

mentioning

confidence: 99%

Quantum-cascade-laser structures as photodetectors

Hofstetter

Beck

Faist

2002

Applied Physics Letters

122

View full text Add to dashboard Cite

We evaluated two different quantum-cascade-laser structures as photodetectors. The first device was a 5.3 m two-phonon-resonance structure, and the second one a 9.3 m bound-to-continuum transition laser. The 5.3 m structure had a peak responsivity of 120 A/W at 2200 cm Ϫ1 and functioned up to 325 K. On the other hand, the 9.3 m device also worked up to 297 K but had a lower responsivity of 50 A/W at 1330 cm Ϫ1 . Since the absorption peak of these devices can be shifted by applying an external bias, we envision interesting applications in free-space optical telecommunications.Quantum well infrared detectors ͑QWIPs͒ for thermal imaging systems have been investigated extensively for several years. Today's state-of-the-art systems consist of arrays with thousands of QWIPs which can detect thermal images at high resolution and with a low background limited infrared performance temperature. 1,2 The detectors used in these systems are optimized for high sensitivity and function usually at cryogenic temperatures. Recently, new applications such as high speed modulators and detectors based on intersubband transitions have been proposed. 3 Because of the short intrinsic carrier lifetimes observed in intersubband transitions, this type of infrared detector should have superior high frequency properties than comparable HgCdTe-based interband photodetectors. 4 Although the responsivity of QWIPs, especially at room temperature, is relatively low, the possibility of having them monolithically integrated with active components, for instance lasers, offers entirely new avenues for telecommunication systems based on intersubband devices. The most important feature of detectors in such systems is their high speed which determines the maximal bandwidth. Although telecommunication experiments using directly modulated quantum-casade ͑QC͒ lasers have so far relied on HgCdTe detectors, 5,6 intersubband detectors and intra-cavity modulators seem to be better suited for this task. Accordingly, we present in this article two examples of how QC structures can be used as infrared photodetectors at temperatures up to room temperature.Growth of the samples for the presented experiments was based on molecular beam epitaxy of lattice matched In 0.53 Ga 0.47 As/In 0.52 Al 0.48 As layers for S1848 and of straincompensated In 0.6 Ga 0.4 As/In 0.44 Al 0.56 As layers for S1869. Both structures were grown on InP substrates; S1848 was a bound-to-continuum transition laser at 9.3 m, while S1869 was a two-phonon-resonance laser structure with an emission wavelength of 5.3 m. The two lasers along with the corresponding measurement results are described in detail elsewhere. 7,8 The 9.3 m bound-to-continuum device was processed into 200ϫ200 m 2 square mesa structures with a 45°facet for efficient light coupling. For the 5.3 m device, we chose a 300-m-long and 40-m-wide ridge waveguide architecture with a cleaved back facet and a 45°tilted front facet. For testing, we soldered the samples on copper heat sinks and mounted them into a liquid nitrogen flow cry...

show abstract

Long wavelength infrared 128*128 Al/sub x/Ga/sub 1-x/As/GaAs quantum well infrared camera and imaging system

Cited by 61 publications

References 13 publications

Large format long-wavelength infrared narrow-band, multi-band, and broad-band QWIP focal plane arrays

Large format long-wavelength infrared narrow-band, multi-band, and broad-band QWIP focal plane arrays

Large-format broadband multicolor GaAs/AlGaAs quantum well infrared photodetector (QWIP) focal plane arrays

Quantum-cascade-laser structures as photodetectors

Contact Info

Product

Resources

About