The polarization approach to registration femtosecond time slots based stimulated photon echo on the exciton statesI.I. Popov, N.S. Vashurin, S.E. Putilin, E.A. Vinogradov and A.U. BahodurEPJ Web Conf., 132 (2017) 02017DOI: https://doi.org/10.1051/epjconf/201713202017