Photon Drag IR-Detectors — the Doppler Effect in the Intersubband Resonance of 2-D Electron Systems

Abstract

Only recently, it has been predicted ^1,2 and demonstrated ³ that the intersubband resonance transition in quantum well systems can be used to obtain a photon drag current. The striking feature of this photo-current is that it flows either parallel or anti-parallel to the direction of the radiation propagation; the sign of the current reverses at the intersubband resonance wavelength. The sign-reversal of the drag direction has a close analogue in the Doppler-effect-induced drift of atoms, the so-called light induced drift (LID).⁴ Because the photon drag effect (PDE) does not involve any charge separation, space charge regions or gradient-induced drift currents, the obvious advantages for photon drag detectors are their fast transient signal response and low impedance.