What have we learned from the phase lag in coherent control experiments?

In coherent control experiments the product signal intensity is modulated by interference between two excitation paths. This modulation is produced by varying the relative phase of the electromagnetic fields used to excited the target. It is observed that the modulated signals for different channels may be out of phase with respect to each other. The phase lag between different channels is energy dependent and contains information about the dynamics of the system. This paper explores different mechanisms that produce such phase lags and assesses what may be learned from them.NRC publication: Ye

Experimental and theoretical studies of the channel phase in the coherent control of molecular processes

The source of the phase lag between different product channels in coherent control experiments is explored. It is shown theoretically that a structured continuum is required to obtain a non-zero channel phase. An isotope effect in the photoionization of HI and DI suggests a direct coupling between electronic and nuclear degrees of freedom. The occurrence of a channel phase is explained also in the context of multichannel quantum defect theory, resolving an earlier controversy.NRC publication: Ye

Above-threshold dissociative ionization in the intermediate intensity regime

The problem of dissociative ionization at intermediate intensities ( 1010\ufffd1012 W cm-2) was studied using the example of I2 and the technique of velocity map imaging. Several new phenomena were observed, including a continuous distribution of recoil energies peaked at zero-kinetic energy, a set of constant dissociative ionic states, and strong anisotropy of the fragment velocity distribution that is diminished by intermediate resonances.NRC publication: Ye