The 3 Most Common Types of Laser Marking

UV laser engraving uses ultraviolet light and high absorption to mark materials. The UV laser engraving process is known as “cold marking” because it does not add heat stress or burn the material. The laser marking machine creates a UV beam using two nonlinear crystals as the passageway. It shoots a 1064 nm laser beam through the crystals to convert the beam to a 355 nm laser.

UV Laser Marking vs. Different Types of Laser Engravers

Manufacturers often choose UV over other types of laser engravers because it marks well on heat-resistant and heat-sensitive materials. It has a strong enough beam to evaporate heat resistance materials, but the cold marking technique prevents heat stress on heat-sensitive materials. Not only that, but UV laser marking outperforms other types of laser engravers on highly reflective materials like copper, silver, and gold.

Fibre engraving gets its name from the fibre resonator intensifying the 1090 nm laser beam. The fibre resonator makes fibre laser machines have notably high output power and engraving speed.

Fibre Engraving vs. Different Types of Laser Engravers

Fibre engraving is the best choice when looking to achieve significant depth on metal products due to its high output power. UV and CO₂ types of laser engravers cannot achieve the high contrast marks or deep engraving on metals that fibre lasers can. These deep and high contrast marks withstand painting and corrosion, which is perfect for parts exposed to harsh environments.
Additionally, the high output makes fibre laser engraving a speedy process for repeated tasks. However, the high output can be damaging to heat-sensitive surfaces.

CO₂ laser engravers work by generating plasma and CO₂ gas inside of a tube, amplifying that light between a reflective mirror and output coupler, and then output as a laser beam. The output laser beam has a wavelength of 10600 nm.

CO₂ Engraving vs. Different Types of Laser Engravers

CO₂ engraving machines have the longest wavelength of all lasers, so they have the most heat transfer. Some materials benefit from heat transfer because of their high heat resistance, while others, like metal, cannot physically be marked by CO₂ lasers. Shallow engraving is ideal for materials that do well with CO₂ engraving.

Annealing, also known as carbon migration, is a style of laser marking that is extremely popular in the aerospace and medical industries as it leaves behind a mark that is highly contrasting and easy to see, but does not raise the surface of the material or create any depth, thus allowing parts to still meet tight surface finish specifications and tolerances. This is achieved by de-focusing the laser to spread the heat over a wider beam spot. This act pulls the carbon content of the material to surface level, creating a visible mark.

This marking style is achieved only on ferrous materials.

Dark marking, often referred to as oxidising, is the act of burning the top layer of material to create a dark contrasting mark. This is extremely common on metal surfaces and often creates a mark that raises the materials surface.

A white marking, also known as an etch, is achieved via light surface roughening of a component. The roughened surface alters the materials' reflectivity producing a white contrast. This white marking can be achieved by each type of laser, depending on the target material.

Nevertheless, engraving and colour marking are widely used across materials, products, and industries. There are many uses in these types of laser marking categories, from using a CO₂ laser for engraving to a fibre laser for annealing.
If you’re looking for more information about lasers, whether that be types of laser marking, types of laser engravers, or different types of laser machines, ask KEYENCE!
At KEYENCE, we specialise in laser technology. Our laser technology is used in measurement devices, marking devices, microscopes, and more. Regardless of your industry, prior laser knowledge, or manufacturing goals, we are here to help you learn more about lasers! Contact us today to learn more information about different types of laser machines.