Controlling rotational state distributions using two-pulse stimulated Raman excitation

Controlling rotational state distributions using two-pulse stimulated Raman excitation

Pulse Function for Control of the Coherent Excitation in Stimulated Raman Spectroscopy

A selective excitation of closely spaced Raman transitions using femtosecond pulse shaping is studied within a semiclassical approach. An analytical pulse function is proposed having duration T that selectively excites one of two transitions separated by a frequency interval less than 1/T. It is shown that, for intense fields, both the field amplitude and pulse frequency spectrum have to be car...

Studying Stimulated Raman Activity in Surface-Enhanced Femtosecond Stimulated Raman Spectroscopy by Varying the Excitation Wavelength.

We present the first multiwavelength surface-enhanced femtosecond stimulated Raman spectroscopy (SE-FSRS) study, as well as the first observation of anti-Stokes vibrational features in SE-FSRS spectra. We compare stimulated Raman loss (SRL) and stimulated Raman gain (SRG) signals at three pump wavelengths chosen to sample different portions of nanoparticle aggregate localized surface plasmon re...

On the role of coupling in mode selective excitation using ultrafast pulse shaping in stimulated Raman spectroscopy.

The coherence of two coupled two-level systems, representing vibrational modes in a semiclassical model, is calculated in weak and strong fields for various coupling schemes and for different relative phases between initial state amplitudes. A relative phase equal to pi projects the system into a dark state. The selective excitation of one of the two, two-level systems is studied as a function ...

Controlling population of the molecular rotational state and the alignment theoretically by tailored femtosecond laser pulse

We demonstrate that the population of the molecular rotational state through a stimulated impulsive Raman excitation can be controlled by tailoring the femtosecond laser pulse with a V-style phase modulation. The results show that, by precisely manipulating the modulation parameters, both the odd and even populations of the molecular rotational state can be completely suppressed or reconstructe...