The laser photolysis of trisilane at 193 nm was studied. The final photolysis products were monosilane, disilane and tetrasilanes. The results were indicative of the participation in the photolysis process of at least two different dissociation pathways which account for about 80% of the total parent molecule dissociation. ArF laser multiphoton dissociation of Si3H8 in a free jet expansion was also studied. Photofragment fluorescence from SiH(A2Δ) and several singlet and triplet excited states of the silicon atom was observed. The rovibrational population distributions in SiH(A2Δ) were obtained by spectral simulation. The rotational distributions can be characterized by near-Boltzmann distributions. The average rotational energies in ν = 0 and ν = 1 are 1550 and 1140 cm−1 respectively and the average vibrational energy in the observed vibrational levels (ν = 0–2) is 800 cm−1. Financial support from the Spanish DGICYT (PB93-0145-CO2-01), Universidad San Pablo-CEU (project no.13/95) and the Human Capital and Mobility Programme of the European Community (CHRX-CT94-0485) is acknowledged.