We have investigated the laser excitation of CaAr collision pairs in a molecular beam experiment with differential detection. The metastable Ca(4s3d)D-1 state is populated by a collision-assisted transition. Measurements of differential cross-sections are reported showing interference structures. The spectral dependence of the signal intensity is characterized by the presence of a satellite structure in the Sigma-Sigma transition and the asymptotically vanishing dipole function. The experimental data are in good agreement with ab initio theoretical results. (C) 2003 Elsevier B.V. All rights reserved.