Intensity dependent dynamics of photoinduced absorption in $CdS_{0.4}$/$Se_{0.6}$ semiconductor doped glasses below the band gap was investigated by using time-resolved differential transmittance spectroscopy. The carriers populated through ultrafast trapping at semiconductor-glass interfaces give rise to a broad photoinduced absorption below the band gap. The decay time of transient absorption depends strongly on the excitation intensity. Based on our results, the physical mechanism for photoinduced absorption processes was suggested.