Strong-field Fourier transform vibrational spectroscopy of methanol cation and its isotopologues using few-cycle near-infrared laser pulses

ABSTRACT

Pump-probe measurements of methanol and its isotopologues (CH₃OH, CH₃OD and CD₃OH) were performed using near-infrared few-cycle intense laser pulses. The yields of the parent ion and the fragment ions oscillate as a function of the pump-probe time delay, reflecting the time evolution of the vibrational wave packet created in methanol and methanol cation by the pump pulse. By the Fourier transform (FT) of the time-domain data, the vibrational mode frequencies of methanol and methanol cations were determined on the basis of the assignment of the peak profiles in the FT spectra made using their relative phases and the theoretical vibrational frequencies and potential energy distributions.

GRAPHICAL ABSTRACT

KEYWORDS:

• Methanol cation
• intense laser fields
• ultrafast molecular dynamics
• strong-field Fourier transform spectroscopy
• vibrational spectroscopy

Additional information

Funding

This work was supported by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan under [grant number JP19002006], [grant number JP24245003] and [grant number JP15H05696].