ABSTRACT
A metallic surface has loosely held electrons that are easily polarized by light. Once a pulse of light has been reflected, the electrons in a mirror return to their original state provided the light was relatively weak. Scattering from any surface is also closely related to reflection; however, we differentiate it from reflection because of multiple scattering surfaces. In addition, there is a type of scattering process in which the resulting photons have a different energy from the photons in the laser pulse. The loss of energy results from a spontaneous quantum transition in which the medium gains energy, for example, through excitation of vibrations. This inelastic process is known as Raman scattering. The ability of a femtosecond laser pulse to create wave packets, with a temporal resolution limited by the duration of the pulse, is what allowed the observation of a chemical bond being broken.
