Chapter 11
Optical Diagnostics with Ultrafast and Strong
Field Raman Techniques
Frederic Chaussard, Bruno Lavorel, Edouard Hertz, and Olivier Faucher
Abstract In this chapter, we will discuss some coherent techniques, namely Raman Induced Polarization Spectroscopy (RIPS) and femtosecond Coherent Raman
Anti-Stokes Spectroscopy (fs-CARS). We will demonstrate their ability to be used
as non-invasive optical diagnostic tools for temperature, density, or concentration
measurements, as well as a means of testing collision induced energy transfer models (in a low field regime), and studying the so-called inhomogeneous lineshape
effects that are particularly enhanced in the case of hydrogen. We will also show
how molecular alignment achieved in a strong field regime can provide additional
information about collisional relaxation processes. In all cases, a precise knowledge
of the collisional effects is required, and so a general modeling of collisional relaxations will be detailed.
11.1 Introduction
Nonlinear coherent interactions of molecules with ultrashort laser pulses remain outstanding means to deduce the properties of gas-phase species (such as
spectroscopic constants), as well as to get information about the environment
of molecules. This is generally performed in a low field regime (perturbative
regime). On the other hand, with intense laser fields, the spatial manipulation of
molecules, especially molecular alignment and orientation, becomes possible, even
under field-free conditions. Though seemingly different at first sight, these topF. Chaussard · B. Lavorel · E. Hertz · O. Faucher (B)
Laboratoire Interdisciplinaire CARNOT de Bourgogne (ICB), UMR 6303 CNRS–Université de
Bourgogne, BP 47870, 21078 Dijon Cedex, France
e-mail: olivier.faucher@u-bourgogne.fr
F. Chaussard
e-mail: frederic.chaussard@u-bourgogne.fr
B. Lavorel
e-mail: bruno.lavorel@u-bourgogne.fr
E. Hertz
e-mail: edouard.hertz@u-bourgogne.fr
R. de Nalda, L. Bañares (eds.), Ultrafast Phenomena in Molecular Sciences,
Springer Series in Chemical Physics 107, DOI 10.1007/978-3-319-02051-8_11,
© Springer International Publishing Switzerland 2014
263
Optical Diagnostics with Ultrafast and Strong
Field Raman Techniques
Frederic Chaussard, Bruno Lavorel, Edouard Hertz, and Olivier Faucher
Abstract In this chapter, we will discuss some coherent techniques, namely Raman Induced Polarization Spectroscopy (RIPS) and femtosecond Coherent Raman
Anti-Stokes Spectroscopy (fs-CARS). We will demonstrate their ability to be used
as non-invasive optical diagnostic tools for temperature, density, or concentration
measurements, as well as a means of testing collision induced energy transfer models (in a low field regime), and studying the so-called inhomogeneous lineshape
effects that are particularly enhanced in the case of hydrogen. We will also show
how molecular alignment achieved in a strong field regime can provide additional
information about collisional relaxation processes. In all cases, a precise knowledge
of the collisional effects is required, and so a general modeling of collisional relaxations will be detailed.
11.1 Introduction
Nonlinear coherent interactions of molecules with ultrashort laser pulses remain outstanding means to deduce the properties of gas-phase species (such as
spectroscopic constants), as well as to get information about the environment
of molecules. This is generally performed in a low field regime (perturbative
regime). On the other hand, with intense laser fields, the spatial manipulation of
molecules, especially molecular alignment and orientation, becomes possible, even
under field-free conditions. Though seemingly different at first sight, these topF. Chaussard · B. Lavorel · E. Hertz · O. Faucher (B)
Laboratoire Interdisciplinaire CARNOT de Bourgogne (ICB), UMR 6303 CNRS–Université de
Bourgogne, BP 47870, 21078 Dijon Cedex, France
e-mail: olivier.faucher@u-bourgogne.fr
F. Chaussard
e-mail: frederic.chaussard@u-bourgogne.fr
B. Lavorel
e-mail: bruno.lavorel@u-bourgogne.fr
E. Hertz
e-mail: edouard.hertz@u-bourgogne.fr
R. de Nalda, L. Bañares (eds.), Ultrafast Phenomena in Molecular Sciences,
Springer Series in Chemical Physics 107, DOI 10.1007/978-3-319-02051-8_11,
© Springer International Publishing Switzerland 2014
263