Controlling the branching ratio of the photodissociation of aligned Cl2 at 404 nm

Non-resonant infrared Nd3+:YAG laser pulses at 1.06 mum were used to align chlorine molecules in a cold molecular beam. The degree of alignment was demonstrated by measurement of the velocity anisotropy of the photofragment Cl(P-2(3/2)) atoms from Cl-2(X(1)Sigma (+)(g)) + 404 nm --> Cl-2((BIIu+)-I-3, Omega = 0) --> Cl(P-2(3/2)) + Cl(P-2(1/2)). The branching ratio of the photoexcitation to Cl-2((BIIu+)-I-3, Omega= 0) with respect to Cl-2((IIu)-I-1, Omega = 1) was controlled, allowing the selectivity of the two different adiabatic photodissociation channels: Cl(P-2(3/2)) + Cl(P-2(1/2)) and Cl(P-2(3/2)) + Cl(P-2(3/2)). (C) 2001 Elsevier Science B.V. All rights reserved.