Calculation of the signal time-profile in transient CARS experiments

✍ Scribed by R. Torre; R. Righini; P. Foggi; L. Angeloni

• Publisher: Springer
• Year: 1991
• Tongue: English
• Weight: 596 KB
• Volume: 52
• Category: Article
• ISSN: 0721-7269
• DOI: 10.1007/bf00357667

✦ Synopsis

The expressions for the resonant and non-resonant contributions to the CARS signal in a time-resolved CARS experiment are derived on the basis of a diagrammatic perturbative expansion of the polarization. The laser fields are assumed to be off-resonance with respect to any electronic level of the system. The probe pulse is supposed to be derived from one of the two pump pulses (091). Under this assumption the effect of the noise content of c01 laser pulses on the signal time-profile (coherence artefact) is correctly reproduced by modelling the noise as a stationary stochastic process. The choice of appropriate polarization geometries is shown to allow for direct measurement of the individual contributions to the CARS signal; the experiments performed on a KC104 single crystal fully confirm the results of the calculation based on our theoretical treatment.