Laser radiation has three fundamental properties: monochromatic, high coherence, and parallel laser waves due to coherence.
Coherence is a fixed relationship between the phase of waves in a beam of radiation in a single frequency, and is coherent when the waves are constant. Having a high coherence parallel laser beam will produce a quality reaction into the surface of materials that react to this beam.
There are many benefits offered from operating a system with coherence, such as the ability to produce a consistent high-quality output when laser processing materials, as well as sharper engravings, straighter cutting, and even pin sharp marking for years of worry-free operation.
Monochromatic refers to wavelength of the radiation, and how the wavelength reacts differently to each surface of a variety of materials. A CO2 laser offers a monochromatic wavelength that has been found to produce quality cutting, marking, and engraving into more materials than any other wavelength.
-Josh Stephens, Trotec Laser