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

Non-resonant infrared Nd3+:YAG laser pulses at 1.06 μm 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(2P3/2) atoms from Cl2(X1Σg+)+404 nm→Cl2(B3Πu+,Ω=0)→Cl(2P3/2)+Cl(2P1/2). The branching ratio of the photoexcitation to Cl2(B3Πu+,Ω=0) with respect to Cl2(1Πu,Ω=1) was controlled, allowing the selectivity of the two different adiabatic photodissociation channels: Cl(2P3/2)+Cl(2P1/2) and Cl(2P3/2)+Cl(2P3/2).