Dissociative ionization of ethanol in chirped intense laser fields

The chemical bond breaking processes of ethanol C₂H₅OH in an intense laser field were investigated by choosing the linear chirp rate of the laser field as only one control parameter. Emphasis was on how the competition between the C-C bond breaking and the C-O bond breaking is affected by the chirp rate of the intense laser field. From the dependences of the yields of the molecular fragment ions such as C₂H₄OH⁺, CH₂OH⁺, C₂H₅⁺, OH⁺, and CH₃⁺, on the linear chirp rate, the temporal evolution of the nuclear wave packet at the singly charged stage was elucidated. The observed skeletal bond breaking processes were interpreted well in terms of holding time during which the light-dressed potential energy surface (LDPES) is maintained to guide the wave packet flow either towards the C-C bond elongation or towards the C-O bond elongation.