(1+1)-REMPI spectra of initially oriented, surface-scattered molecules. (1+1)-REMPI spectra of initially oriented, surface-scattered molecules. Spectra cover the range of the A2Σ+(v = 0) ← X2Π(v = 2) and the A2Σ+(v = 0) ← X2Π(v = 3) bands (see assignment on top of spectra). (A) Spectrum obtained for the N-front favored orientation distribution in the incident (v = 3, J = 0.5) beam. (B) Spectrum obtained for the O-front favored orientation. We normalized the signal strength to the REMPI laser pulse energy. Bartels N et al. PNAS 2013;110:17738-17743 ©2013 by National Academy of Sciences