Hawker, P.P.HawkerKent, A.A.KentChallis, L.L.ChallisBartels, A.A.BartelsDekorsy, T.T.DekorsyKurz, H.H.KurzKöhler, KlausKlausKöhler2022-03-032022-03-032000https://publica.fraunhofer.de/handle/publica/19736210.1063/1.1324981We have used pulse time-of-flight techniques to examine the phonon emission from an optically excited GaAs/AlAs superlattice structure. For laser excitation wavelengths shorter than 767 nm (the energy of E1HH1 transition), we detect a significant longitudinal acoustic phonon component directed in a narrow beam normal to the structure. Under identical excitation conditions, generation of coherent longitudinal acoustic phonons has previously been observed in this structure. We suggest that the excitation wavelength and angular characteristics of the longitudinal acoustic emission is consistent with those of propagating modes produced as coherent phonons "leak" from, the superlattice structure.enIII-V semiconductorIII-V HalbleitersuperlatticeÜbergitteroptical measurementoptische Messung621667journal article