Komori, K.Hayes, G. R.Deveaud, B.Wang, X. L.Ogura, M.Watanabe, M.2007-08-312007-08-312007-08-31200210.1002/1521-396X(200204)190:3%3C855::AID-PSSA855%3E3.0.CO;2-%23https://infoscience.epfl.ch/handle/20.500.14299/11478WOS:000175657000046591We have investigated the ultrafast coherent dynamics of exciton-polaritons and excitons in semiconductor quantum nanostructures, including InGaAs/AlGaAs multi quantum well Bragg structures and AlGaAs/GaAs crescent shaped quantum wire samples, by using a phase-locked spectroscopic technique. In the multi quantum well Bragg sample, a two-stage decay due to the superradiant exciton-polariton mode is clearly observed at the resonant condition. In the crescent shaped quantum wire sample, the highly sensitive coherent control measurement enables us to observe the dephasing characteristics and a very fast dephasing time T-2 of 200 to 300 Is with power dependence was observed.SUBSTRATEWIREStext::journal::journal article::research article