Ultrashort pulse lasers which provide sufficient output power for industrial applications offer pulse lengths in the range from some 10 picoseconds to some 100 femtoseconds. They can be used for laser cutting, drilling, laser marking or surface treatment applications. Ultrashort pulses are shorter than the time needed for most energy diffusion processes within the atomic lattice. Therefore no heat is transferred to surrounding material which eliminates any unwanted material change. This is the reason why the method is referred to as 'cold'.