Chirped pulse amplification (CPA) is a technique for amplifying an ultrashort laser pulse up to the petawatt level with the laser pulse being stretched out temporally and spectrally prior to amplification. CPA is the current state of the art technique which all of the highest power lasers (greater than about 100 terawatts, with the exception of the ~500 TW National Ignition Facility) in the world currently utilize.

A tightly focused laser beam can achieve a local temperature of over 6,000 Celsius degree. Even with rapid heat conduction to environment, the high temperature is sufficient to melt almost all materials (except ceramics), cause chemical decomposition, and lead to oxidation and deposition, all at spatially controlled location. The right photo is an infrared camera image taken while a CO2 laser is moving across a substrate (image taken from Applied Optics 2018, 57, 4232)

Our fiber laser markers can be operated at different frequency (pulse width) of laser beam. Photothermal effect dominates in long pulse (nanosecond, low frequency), and leads to engraving; photoablation dominates in short pulse (picosecond, high frequency), and lead to ablation or removal of materials. By switching between high and low frequencies, our laser markers can produce deep structures on metals via layer-by-layer removal of materials. 

In Cartesian control, laser beam is fixed and the object moves in XY coordinates. In hybrid control, the material moves in Y direction and laser beam in X direction (flying optic system). In Galvanometer control, a pair of live mirrors is placed before focusing lens. These mirrors are attached to small, yet quick analog or digital electric motors (galvos). By altering the angle of the mirrors using galvos, the beam is guided within a limited area, through an F-theta lens onto the material. An advantage of Galvanometer control is high speed. By attaching a third mirror, curved or highly stepped objects can be marked to achieve 3D ability.