Dresden 2017 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 63: Poster: Quantum Dots and Optics
HL 63.1: Poster
Mittwoch, 22. März 2017, 15:00–19:00, P1A
Time-resolved optical spectroscopy of guiding modes a in CdZnTe/CdMgTe structure — •Jonas Vondran1, Felix Spitzer1, Nils Weber2, Régis Andre3, Henri Mariette3, Cedrik Meier2, Torsten Meier2, Ilya Akimov1, and Manfred Bayer1 — 1Technische Universität Dortmund, Dortmund, Germany — 2Universität Paderborn, Paderborn, Germany — 3Université Grenoble-Alpes, Grenoble, France
We report on pump-probe reflectivity measurements with 30 fs temporal resolution in a 170 nm thick CdZnTe waveguiding layer cladded between 100 nm width CdMgTe cap and 400 nm thick buffer layer. In order to excite and detect guiding modes gold gratings with periods from 230 to 310 nm are patterned at the top of the sample. Steady state measurements show distinct polarization, angle and wavelength-dependent features indicating the dispersion of waveguiding modes and their interaction with the excitonic resonance at 760 nm wavelength. The transient optical response is strongly influenced by the polarization of pump and probe beams as well as the grating period. The largest modulation depth is observed when the modes are resonantly excited in TM-polarization. We observe clear signatures of free induction decay at negative delay times when the probe reaches the sample earlier than the pump pulse with coherence times of 80-120 fs at T=10K.