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Quantum-well infrared photodetector with voltage-switchable quadratic and linear response

Quantumwell-Infrarot-Photodetektoren mit spannungs-schaltbarer quadratischer und linearer Responsivität
: Maier, T.; Schneider, H.; Liu, H.C.; Walther, M.; Koidl, P.


Applied Physics Letters 88 (2006), No.5, Art. 051117, 3 pp.
ISSN: 0003-6951
ISSN: 1077-3118
Journal Article
Fraunhofer IAF ()
quantum well infrared photodetector; Quantumwell Infrarot-Photodetektor; two photon absorption; Zwei-Photon-Absorption; infrared detector; Infrarotdetektor; Qwip; infrared; Infrarot

We present a quantum-well infrared photodetector that allows us to switch between a quadratic and a linear detection mode. We employ an asymmetric detector design where intersubband transitions in a three-level system give rise to a quadratic power dependence down to very low excitation densities. Upon reversing the bias voltage, however, the intermediate subband acts as the ejection channel due to highly efficient tunneling, thus leading to a two-level system with linear photoresponse.