Fig. 1: Schematic representation of the experimental technique and the sample.
From: Extending the time of coherent optical response in ensemble of singly-charged InGaAs quantum dots
a Photoluminescence (PL, doted line) and transmission (dashed line) spectra of the sample measured at the temperature T = 6 K. The PL spectrum is shown for lateral emission from the edge of the sample in the direction parallel to its plane, e.g. along x-axis. The laser spectrum is shown with a solid line. b Sketch of the photon echo experiment. (In,Ga)As quantum dots (QDs) are embedded in a microcavity with GaAs/AlAs distributed Bragg reflectors (DBR). c Blue line shows the transient four-wave mixing (FWM) signal measured in kS = 2k2−k1 direction for τ12 = 33.3 ps and τ23 = 100 ps. The signal is represented by the two-pulse PE (2PE) at 67 ps and the three-pulse PE (3PE) at 167 ps. The three peaks with filled area show the temporal position of excitation laser pulses. Labels on top correspond to the polarization of excitation and detection in the HVVH configuration. H and V correspond to linear polarizations along x and y axes, respectively.
