COMPLETE DESCRIPTION OF 2-PHOTON(1+1') IONIZATION OF NO DEDUCED FROM ROTATIONALLY RESOLVED PHOTOELECTRON ANGULAR-DISTRIBUTIONS

Time-of-flight photoelectron spectroscopy has been used to record energy-resolved photoelectron angular distributions (PADs) following (1 + 1') resonance-enhanced multiphoton ionization (REMPI) of NO via the upsilon-i = 1,N(i) = 22 rovibrational level of the A 2-SIGMA+ state. The PADs corresponding to single rotational states of the resulting molecular ion show a strong dependence on the change in ion core rotation DELTA-N ( = N+ -N(i)) and also on the angle between the linear polarization vectors of the two light beams. Broken reflection symmetry [I(theta,phi) not-equal I(- theta,phi)] is observed when the polarization vectors of the two light beams form an angle of 54.7-degrees. A fit to the PADs provides a complete description of this molecular photoionization, namely, the magnitudes and phases of the radial dipole matrix elements that connect the intermediate state to the \l-lambda> photoelectron partial waves (Refs. 1 and 2). This information is then used to predict unobserved quantities, such as ion angular momentum alignment and the full three-dimensional form of the PADs.