What is laser marking and how marking machines work

Laser marking is the process of permanently marking a surface using a focused beam of light. It can be performed using different types of lasers including fibre lasers, CO2 lasers, pulsed lasers and continuous lasers. 

The three most common laser marking applications are:

Laser engraving: creates deep and permanent marks that are resistant to wear and tear

Laser Etching: Creates high contrast permanent marks at high speeds.

Laser Annealing: Creates a mark under the surface without affecting the base metal or its protective coatings.

Laser marking machines can mark a wide range of materials such as steel, aluminium, stainless steel, polymers and rubber. It is commonly used to identify parts and products by 2D barcodes (Data Matrix or QR codes), alphanumeric serial numbers, VIN numbers and logos.

How do laser marking machines work?

In order to create long-lasting marks, laser marking systems produce a focused beam of light that contains a high amount of energy. When the laser beam strikes a surface, its energy is transferred in the form of heat, creating black, white and sometimes coloured markings.

The Science of Lasers

Laser beams are produced by a reaction called "LASER", which stands for Light Amplification by Stimulated Emission of Radiation. First, a special material is excited with energy, causing it to release photons. The newly released photons then stimulate the material again, producing more and more photons. This produces an exponential number of photons (or light energy) in the laser cavity. This accumulation of energy is released in the form of a single coherent beam, which is directed to the target using mirrors. Depending on the energy level, it can etch, engrave or anneal surfaces with extreme precision. And while different laser markers can mark different materials, laser energy is measured in wavelengths or nanometres (nm). Specific wavelengths are used for different applications and can only be produced by certain types of lasers.