Photolysis of ICl causes mass-dependent interference in the Cl(2P3/2) photofragment angular momentum distributions

We have studied the photodissociation of ICl using linearly polarized light at 532 nm. This wavelength excites several electronic states. Using linearly polarized probe light, we have measured the angular momentum distributions of the Cl-35(P-2(3/2)) and Cl-37(P-2(3/2)) photofragments, which are found to differ significantly. These distributions are expressed in a multipole moment expansion having four terms. These terms can be classified as incoherent contributions from parallel and perpendicular transitions, and coherent contributions from interference that arises from these interacting states. Analysis of these angular momentum distributions using this formalism shows that the incoherent contributions from the dissociating surfaces are mass independent, whereas the coherent contributions are mass dependent. (C) 1998 American Institute of Physics. [S0021-9606(98)03720-9]