Channel-resolved angular correlation between photoelectron emission and fragment ion recoil of ethanol in intense laser fields

We investigate multi-channel dissociative ionization of ethanol in intense near-infrared laser fields with photoelectron-photoion coincidence three-dimensional momentum imaging. As the intensity of the linearly polarized laser field increases to 23 TW/cm^2, phoelectrons are dominantly emitted along the laser polarization. The photoelectron angular distributions (PADs) are not influenced by the orientation direction of ethanol with respect to the laser polarization direction. In the circularly polarized laser field with 80 TW/cm^2, the photoelectron angular distributions of CH3CD2OH in the recoil frame of the CD_2OH^+ and CH_3CD^+_2 channels are obtained. Photoelectrons in the CD_2OH^+ channel are preferentially emitted from the CH_3 moiety at the moment of birth. By the density functional theory, wecalculate the ionization probability in the electric field as a function of its direction. The comparison between the observed and calculated recoil frame (RF)-PADs suggests that the inner valence 10a′ molecular orbital is deformed by the laser field prior to the photoelectron emission. It is clearly shown that there are two pathways, (i) photoelectron emission from 10a′ and (ii) photoelectron emission from 3a′′ (HOMO) followed by photoexcitation. In the CH_3CD^+_2 channel, the RF-PAD is found to be isotropic, suggesting the stepwise processes of photoelectron emission and subsequent photoexcitation