Ultrafast multiplex CARS investigation of vibrational characteristics in chloroform and PMMA

This paper demonstrates the femtosecond time-resolved coherentanti-Stokes Raman scattering by using folded BOXCARS geometry wherean ultrashort broadband coherent white light continuum was used asStokes pulse, and carries out the non-contact detection at longdistance. The CARS signal is so easy to be detected that it can beseen even by nude eye. The C--H bonds of chloroform or PMMA weredetected and the vibration modes belonging to the side chain and themain chain in PMMA were also compared. Their vibrationalcharacteristics involved decay process and quantum beating werediscussed. This modified CARS experimental technique could make upthe deficiency of traditional CARS technique.