Selective control of HOD photodissociation using CW lasers

Abstract

Selective control of HOD photodissociation (H-O + D ← HOD → H + O-D) has been theoretically investigated using CW lasers with appropriate carrier frequency and |0, 0〉, |0, 1〉 and |0, 2〉 with zero quantum of excitation in the O-H bond and zero, one and two quanta of excitation in the O-D bond as the initial states. Results indicate that the O-H bond in HOD can be selectively dissociated with a maximum flux of 87% in the H + O-D channel from the ground vibrational state |0, 0〉. For the O-D bond dissociation, it requires two quanta of excitation (|0, 2〉) in the O-D mode to obtain 83% flux in the H-O + D channel.Use of a two colour laser set-up in conjunction with the field optimized initial state (FOIST) scheme to obtain an optimal linear combination of |0, 0〉 and |0, 1〉 vibrational states as the initial state provides an additional 7% improvement to flux in the H-O + D channel as compared to that from the pure |0, 1〉 state.

Isotope effects on the photodesorption processes of X2O (X = H,D) and HOD ice

“…3,[17][18][19][20] Absorption cross sections of gas-phase H 2 O, 14, 15, 21 D 2 O, 14,15 and HOD 13,15,16 have been calculated for the rovibrational ground state and for rovibrationally excited states, and have also been measured experimentally for gas-phase H 2 O, [18][19][20] D 2 O, 18,19 and HOD. 18,22 Moreover, in other experiments the photon-induced 22 dissociation and ion-induced 23 dissociation processes of gas-phase HOD have been studied, and the branching ratios, which depend on laser frequency, 16,22,24 have been provided. Zhang et al 16 and Engel et al 13 both predicted that the There are also laboratory experiments regarding UV photodissociation of H 2 O and D 2 O ice where the ice sample is irradiated by multi-photon sources at excitation energies close to the Ly-α value.…”