Ultrafast Laser Physics
Ultrafast laser physics is the area of laser physics which is dealing with “ultrafast” processes in lasers, i.e. processes occurring on a time scale of picoseconds, femtoseconds, or faster. Of particular importance are processes concerning the generation of ultrashort pulses of light. Examples of such phenomena are:
- ultrafast nonlinearities in the context of light propagation, such as the Kerr effect, Raman scattering and four-wave mixing
- ultrafast excitation, saturation and relaxation phenomena in semiconductors, such as semiconductor saturable absorber mirrors or laser diodes
- fast processes in laser gain media, e.g. thermalization of the Stark levels within a Stark level manifold of a rare-earth-doped laser crystal
- effects of such phenomena on the pulse formation in lasers (→ mode locking)
It can also be of interest how other phenomena, e.g. chromatic dispersion, influence ultrafast processes.
There is a wider area called ultrafast optics which also covers phenomena outside lasers.