Control of branching ratio in the photofragmentation of DCl+ ions: Effect of initial vibrational state

Photofragmentation of DCl+ ions alternatively leads to the formation of D+ + Cl or Cl+ + D in competing reaction channels. The branching ratio of the product yields D+/Cl+ has been investigated theoretically by numerically solving coupled time dependent Schrodinger equations and experimentally by femtosecond (fs) dissociative ionization of DCl. The theoretical analysis shows that this branching ratio increases step-like at intensities, which characteristically depend on the initial vibrational state for nonresonant multiphoton excitation. In general the threshold decreases with increasing initial vibrational quantum number. Experimental studies exhibit a similar step-like behavior of the D+/Cl+ branching ratio. Here the intensity at which the step occurs characteristically depends on the chirp of the fs-laser pulses, suggesting that different chirp may lead to intermediate DCl+ ions differing in the effective vibrational quantum number.