AC Kerr effect

The present study demonstrates that the analytic calculation of hyperpolarizability dispersion coefficients provides an efficient alternative to the pointwise calculation of dispersion curves. The dispersion coefficients provide additional insight into non-linear optical properties and are transferable between the various optical processes, also to processes not investigated here as for example the ac-Kerr effect or coherent anti-Stokes Raman scattering (CARS), which depend on two independent laser frequencies and would be expensive to study with calculations ex-plictly frequency-dependent calculations. 

X < >o, cofc,-cofc) AC electrooptic effect, AC Kerr effect, Brillouin scattering, Raman scattering. Two-photon absorption High-speed optical gates... 

The Kerr effect is the result of applying an electric field to produce birefringence. This phenomena is commonly observed for both colloidal and polymeric liquids and is used in the characterization of the structure of these materials. Alternatively, by using an AC electric field, a modulation of the polarization of light can be affected. Such devices have rarely been used as modulators but do have the potential of allowing higher frequencies than the more common photoelastic devices. 

Xe(3)(-ffl,ffla,-ffla,ffl) AC electro-optical effect (AC-Kerr)... 

PAP cycle at room temperature the inset shows the same experiment for a DRl/PMMA guest host system. Details of ATR EO modulation experiments can be found elsewhere.Briefly, the EO coefficients of polymer films are determined by applying an ac voltage (ViCosQt) between two metallic layers that sandwich the polymer film, and by recording the modulation of the reflectivity at Q, for the Pockels effect, and at 2Q, for the Kerr effect. A computer program evaluates the amplitudes of modulation of the film s thickness, and the refractive indices, , (i = x, y, 2 which represent the principal axes of the film), from which the Pockels, e.g., and Kerr, e.g., s y, EG coefficients are obtained. These are given by... 

Because of the extensive overlap with electro-optics and nonlinear optics, the reader is referred to separate articles on these topics in this encyclopedia. See ElectroopticAL Applications for a discussion of the changes in the optical response of polymers dne to an applied AC or DC electric field from the so-called Pockels or Kerr effects. Also see, for an overview. Nonlinear Optical Properties. 

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