Fragmentation of dimethyl ether in femtosecond intense field

The fragmentation of dimethyl ether (DME) in intense femtosecond laser field has been studied at 810, 405 and 270 nm with intensities up to 2.48 × 1015, 3.86 × 1015 and 1.62 × 1014 W/cm2, respectively. At 405 nm, DME is possibly firstly ionized by multiphoton absorption, and then parent ion DME+ dissociates into fragments via filed-induced dissociation. For 810 and 270 nm laser fields, DME firstly dissociates into CH3O and CH3 fragments and then these neutral fragments are ionized by field tunneling. Another possible way for DME to dissociate at 810 and 270 nm is that DME is ionized by intense field ejection of inner valance electron and then the excited DME+ dissociates into fragment ions. Ultrafast rearrangement of DME or DME+ in intense field may be responsible to the unpredictable fragment ions, CHO+/C2H5+andH2+.