The dissociative ionization and Coulomb explosion of ethane by a femtosecond laser field

Femtosecond laser-induced dissociation and Coulomb explosion of polyatomic molecule C_2H_6 were systematically investigated using a time-of-flight mass spectrometer and a chirped pulse amplifier laser. With the laser intensity varying from 2.4\times10^15W/cm^2 to 1.2\times10^16W/cm^2, strong molecular ions C_2H_n^+ (n=0－6) and atomic ions C^m+ (m=1－3) signals were observed. The double-peak structure of atomic ions indicated the occurrence of Coulomb explosion. Compared with the nearly isotropic distribution of C^+, highly charged ions C^m+ (m=2－3) exhibited a sharply anisotropic angular distribution, which was attributed to the geometric alignment.