Dr. Anjali Singh Profile

Dr. Anjali Singh

Retired

SPIE Involvement:

Author

Publications (17)

Proceedings Article | 12 April 2021 Presentation

The photonics project web based electro-optical tools

John Devitt, Ron Driggers, Anjali Singh, Orges Furxhi, Mel Friedman, Chris Mendes, Jamal Mustafa

Proceedings Volume 11740, 117400U (2021) https://doi.org/10.1117/12.2591825

KEYWORDS: Photonics, Electro optics, Radio optics, Photonic devices, Infrared radiation, Infrared imaging, Imaging devices, Electro optical systems, Computer programming

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Proceedings Article | 13 February 2016 Paper

Examples of modern quantum sensing and metrology with new results on photon-added coherent states

Jerome Luine, Anjali Singh, Bryan Gard, Jonathan Olson

Proceedings Volume 9755, 97552G (2016) https://doi.org/10.1117/12.2217161

KEYWORDS: Photon counting, Picture Archiving and Communication System, Photodetectors, Interferometers, Time correlated photon counting, Beam splitters, Single photon, Signal detection

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Proceedings Article | 13 February 2016 Paper

Mid-infrared interband cascade photodetectors with high quantum efficiency

Zhao-Bing Tian, Anjali Singh, Kevin Rigg, Sanjay Krishna

Proceedings Volume 9755, 975512 (2016) https://doi.org/10.1117/12.2208217

KEYWORDS: Mid-IR, Photodetectors, Sensors, Quantum efficiency, Quantum wells, Superlattices, Infrared radiation, Absorption, Temperature metrology, External quantum efficiency, Gallium antimonide, Sensor performance

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SPIE Journal Paper | 1 August 1999

Zero-bias offsets in the low-temperature dark current of quantum-well infrared photodetectors

Anjali Singh, David Cardimona

OE, Vol. 38, Issue 08, (August 1999) https://doi.org/10.1117/12.10.1117/1.602184

KEYWORDS: Resistance, Capacitance, Quantum well infrared photodetectors, Quantum wells, Sensors, Data modeling, Circuit switching, Doping, Instrument modeling, Optical engineering

Proceedings Article | 26 July 1999 Paper

8- to 9-um and 14- to 15-um two-color 640x486 GaAs/AlGaAs quantum well infrared photodetector (QWIP) focal plane array camera

Sarath Gunapala, Sumith Bandara, Anjali Singh, John Liu, S. Rafol, Edward Luong, Jason Mumolo, N. Tran, John Vincent, C. Shott, James Long, Paul LeVan

Proceedings Volume 3698, (1999) https://doi.org/10.1117/12.354502

KEYWORDS: Sensors, Staring arrays, Quantum well infrared photodetectors, Long wavelength infrared, Gallium arsenide, Quantum efficiency, Multiplexers, Cameras, Reflectors, Black bodies

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Proceedings Article | 7 April 1999 Paper

Broadband quantum well infrared photodetectors

Sheng Li, Jerome Chu, Jiangchi Chiang, Jung Lee, Anjali Singh

Proceedings Volume 3629, (1999) https://doi.org/10.1117/12.344551

KEYWORDS: Quantum wells, Quantum well infrared photodetectors, Gallium arsenide, Long wavelength infrared, Gallium, Infrared radiation, Electroluminescence, Absorption, Chlorine, Analytical research

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Typical quantum well infrared photodetectors (QWIPs) exhibit rather narrow spectral bandwidth of 1 to 2 micrometer. For certain applications, such as spectroscopy, sensing of a broader range of infrared radiation is highly desirable. In this work, we report the design of five broadband (BB-) QWIPs sensitive over the 7 to 14 micrometer spectral range. Three n- type BB-QWIPs consisting of three, four, and five quantum wells of different thickness and/or composition in a unit cell, which are then repeated 20 times for the three and four quantum wells (QW) devices and 3 times for the five QWs device to create the BB-QWIP structures, are demonstrated. The three- well n-type In_xGa_1-xAs/Al_yGa_1-yAs BB-QWIP is designed to have a response peak at 10 micrometer, with a FWHM bandwidth that varies with the applied bias. A maximum bandwidth of (Delta) (lambda) /(lambda) _p equals 21% was obtained for this device at V_b equals -2 V. The four- well n-type In_xGa_1-xAs/GaAs BB-QWIP not only exhibits a very large responsivity of 2.31 A/W at 10.3 micrometer and V_b equals +4.5 V, but also achieves a broader bandwidth of (Delta) (lambda) /(lambda) _p equals 29% than the three-well device. The five-well n-type In_xGa_{1- x}As/GaAs BB-QWIP has achieved a FWHM bandwidth of (Delta) (lambda) /(lambda) _p equals 28% at V_b equals 1.75 V. In addition, two p-type In_xGa_1-xAs/GaAs BB-QWIPs with variable well thickness and composition, sensitive in the 7 - 14 micrometer spectral range, are also demonstrated. The variable composition p-type BB-QWIP has a very large FWHM bandwidth of (Delta) (lambda) /(lambda) _p equals 48% at V_b equals -1.5 V and T equals 40 K. The variable thickness p- type BB-QWIP was found to have an even broader FWHM bandwidth of (Delta) (lambda) /(lambda) _p equals 63% at V_b equals 1.1 V and T equals 40 K, with a corresponding peak responsivity of 25 mA/W at 10.2 micrometer. The results reveal that p-type BB- QWIPs have a broader and flatter spectral bandwidth but lower responsivity than that of n-type BB-QWIPs under similar operating conditions.