| Popis: |
Vibrational wave packets in chloroform and gold colloid in chloroform were studied by femtosecond pump-probe spectroscopy. It was found that the main modes of oscillations for both systems coincide with the frequencies of the Raman resonances of chloroform 260 cm -1 , 367 cm and 668 cm . The effect of gold nanoparticles leads to 4-6 fold increased signal of Raman resonance of pure chloroform. Nanoparticle, nanoplasmonics, Au, CHCl 3 , femtosecond, pump-probe, Raman 1. INTRODUCTION Femtosecond laser pulses can excite coherent oscillations of molecules nuclei of the medium when the duration of the excitation pulse is shorter than the oscillation period of corresponding modes 1 . For example, the pulse duration of 25 fs can coherently excite a mode with a frequency of up to 1200 cm -1 . Previously reported observation by femtosecond pump-probe spectroscopy coherent vibrational wave packet (coher ent package) in pure chloroform excited by 50 fs pulse with a wavelength of 476 nm |
