Lez #51+52 Principles of advanced microscopies I. RIKES.

 We described the basics of RIKES: a vibrationally resonant combination of pump and stokes can induce optical anisotropy which generates an electric field along a direction orthogonal to the incoming stokes, via a four wave mixing process. This effect can be homodyne detected, or via balanced detection, to measure separately the real and imaginary parts of the non linear susceptibility.

Lez #49+50 Principles of advanced microscopies I. Coherent Vibrational imaging.

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 #47+48 FSRS II: molecular photoexcitations and transient states: the example of Tiophene

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.   

Lez #45+46 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 and a few slides discussed.