Hessler, T.Haacke, S.Pleumeekers, J. L.Selbmann, P. E.Dupertuis, M. A.Deveaud, B.Doussiere, P.Bachmann, M.Emery, J. Y.Ducellier, T.Taylor, R. A.2007-08-312007-08-312007-08-31199710.1002/1521-3951(199711)204:1<574::AID-PSSB574>3.0.CO;2-Fhttps://infoscience.epfl.ch/handle/20.500.14299/11236WOS:A1997YJ65400153Pump and Probe measurements with femtosecond pulses are performed on a Gain-Clamped Semiconductor Optical Amplifier (a special laser structure). The relaxation oscillations of the carriers density are observed directly in the time domain, Reasonable values of the differential gain and the nonlinear gain factors are extracted from the current dependence of the oscillations.GAINtext::journal::journal article::research article