Femtosecond lasers are the shortest pulse duration laser in the industrial marketplace. Typically, industrial femtosecond lasers will have a pulse duration of 300-400 femtoseconds or 300-400 x 10-15 s. When trying to produce a laser that delivers such short packets of light with sufficient pulse energy to enable materials processing, the peak power is so high that it would cause damage to the gain medium. To avoid this, the amplification of the pulse is usually done with a stretched pulse and later compressed. The process of chirped pulse amplification stretches the pulse by a few orders of magnitude so reducing peak power to allow amplification to occur below the damage threshold of the medium. After amplification the pulse is then compressed back to its original pulse duration and beam quality. In some lasers the need to stretch the pulse initially may not be required. The femtosecond laser can also be offered in different wavelengths from IR, green and UV (though UV is not available on every laser) via frequency conversion by non-linear optics. With such a short puls
e duration the laser is able to machine almost any type of material from glass to hardened steel to plastics. As the pulse duration of the laser is shorter than the conduction time of the material, there is no heat signature from processing. The material removal is from solid to vapor - this is often referred to as "cold ablation" - this provides the highest quality machining and offer unique machining capabilities.