Lez #57+58 Coherent vibrational imaging I

 We introduced the basic principles of linear and non linear imaging, with or without vibrational sensitivity. We then discussed the basics of CARS imaging, the nor resonant background issues and how to resolve them.

Lez #55+56 Time-Domain Impulsive Vibrational Spectroscopy

 We discussed the Impulsive Vibrational Scattering technique, in which a pair of temporally separated pulses is used to map vibrational excitations in the time domain. The experimental setup follows a pump-probe scheme, where an ultrashort broadband pump pulse generates vibrational coherences via two interactions with spectral components shifted by one vibrational quantum. The coherences modulate the optical properties of the medium, which are then monitored by a delayed probe. We derived the analytical expressions using the diagrammatic formalism, assuming impulsive beams. On classroom some lecture notes.

Lez #53+54 Dephasing

 We discussed from a microscopic point of view how out-of-diagonal elements of the density matrix are damped due to the interaction with the environment. As a reference, you can use chapter 5 of the “Principles of Nonlinear Optical  Spectroscopy: A Practical Approach” by P. Hamm

Lez #51+52 Esercitazione 2

 Seconda parte della risoluzione del secondo esonero 2022. Risposta HL1 in condizioni di risonanza e fuori risonanza. Risposta di HL2. Interpretazione fisica dei risultati e confronto con la risposta RRS1.

Lez #49+50 Esercitazione 1

Prima parte della risoluzione del secondo esonero 2022. Diagrammi di Hot Luminescence (HL1 e HL2). Calcolo esplicito di HL1.

Lez #47+48 RRS under different pulse temporal profile

We derived an expression for the RRS signal as a function of arbitrary spectral profiles of the Raman pump and probe pulses. This formula was then used to numerically evaluate the Raman gain under different experimental conditions, specifically varying the pump pulse temporal profile and its relative delay with respect to the probe.

Lez #45+46 FSRS II Principles and applications (Vibrational cooling, internal conversion and conical intersections)

 We then discussed the case of MPT studied by FSRS, where an ultrafast motion outside the Franck Condon region is observed, followed by vibrational cooling and singlet to triplet internal conversion. This example illustrates the synergy among transient absorption, FSRS and DFT calculations.