01316nas a2200229 4500008004100000020001400041245006500055210006300120260000800183300001200191490000600203520067700209100001400886700001800900700001900918700002000937700002000957700002000977700002000997700002001017856004901037 1994 eng d a0268-124200aFAR-INFRARED SATURATION SPECTROSCOPY OF A SINGLE SQUARE-WELL0 aFARINFRARED SATURATION SPECTROSCOPY OF A SINGLE SQUAREWELL cMay a627-6290 v93 a
We have performed saturation spectroscopy measurements of the lowest intersubband transition in a single 400 angstrom GaAs/Al0.3Ga0.7As modulation-doped square quantum well. We couple intense tunable far-infrared radiation from the Santa Barbara free electron laser into our sample using an edge-coupling technique and measure absorption as a function of frequency and intensity. Saturation and frequency shifts in the absorption line are clearly observed. We attribute the frequency shifts to reductions in the many-body depolarization shift. From our preliminary measurements, we estimate the intersubband relaxation time to be 600 ps to within a factor of three.
1 aCraig, K.1 aFelix, C., L.1 aHeyman, J., N.1 aMarkelz, A., G.1 aSherwin, M., S.1 aCampman, K., L.1 aHopkins, P., F.1 aGossard, A., C. uhttps://markelz.physics.buffalo.edu/node/264