Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

1 Publication
Two-photon photocurrent studies of electron intersubband dynamics in multiple quantum wells
Schneider, H.;
Quantum wells comprising three equidistant subbands, two of which are bound in the well and the third one in the continuum, result in a resonantly enhanced coefficient for two-photon absorption, which is by six orders of magnitude stronger than in usual semiconductors. Exploiting this nonlinearity in two-photon detectors, quadratic autocorrelation of a free-electron laser has recently been demonstrated at room temperature [1]. Temporal resolution of such a two-photon autocorrelator is only limited by the sub-ps intrinsic time constants of the intersubband transition, namely the intersubband relaxation time and the phase relaxation time. Using sub-ps mid-infrared pulses, the approach allows us to determine systematically the dependence of these time constants on structural parameters, and to discriminate between different scattering processes [2].
[1] H. Schneider, H. C. Liu, S. Winnerl, O. Drachenko, M. Helm, J. Faist, Appl. Phys. Lett. 93, 101114 (2008).
[2] H. Schneider, T. Maier, M. Walther, H. C. Liu, Appl. Phys. Lett. 91, 191116 (2007).
Keywords: intersubband transition, two-photon absorption, quantum well infrared photodetector, phase relaxation, autocorrelation
  • Invited lecture (Conferences)
    International Workshop on Nonequilibrium Nanostructures (NONNA'08), 01.-06.12.2008, Dresden, Germany

Publ.-Id: 11960 - Permalink