Vibrational predissociation of methylnitrite using phase-locked ultrashort laser pulses

We solve numerically the time-dependent Schrödinger equation to study the behavior of a molecule interacting with two phase-locked ultrashort laser pulses. The two-dimensional model used in the calculations mimics the properties of the CH3ONO molecule. The two pulses are identical except for their relative phase and are tuned to excite an upper electronic state of the molecule. After excitation the molecule predissociates and we calculate the dependence of the NO yield and of the NO vibrational population on the delay time between the pulses. Because the molecular wave functions representing the excited states created by each pulse interfere, the total product population created by the joint action of the pulses differs from the total population obtained when the two pulses act independently on the molecule. This type of experiment provides a means of using quantum interference for a modest control of photodissociation.