Nonlinear optics with picosecond laser pulses

7 - Conclusion

Picosecond laser pulses have proved to be an important tool in the measuring of short characteristic times and in several nonlinear optical experiments. In particular they allow the observation of several effects in a transient regime, with new features. An example is given by the Raman effect, whose transient characteristics are in good agreement with the theoretical predictions. Another effect is given by self-focusing which is, in general, due to physical mechanisms faster than the molecular orientational Keer effect, like a molecular «rocking». Finally the use of picosecond pulses has made possible the observation of several new stimulated effects such as scattering in the far wing of the Rayleigh line and low-frequency Raman lines in liquids. This indicates that many physical processes which have not previously been considered should be taken into account through a more complete theoretical description.