What is laser cutting?

Laser cutting is a thermal separation process in which materials are cut using a focused laser beam for example, in applications such as laser depaneling of printed circuit boards. The high-energy beam heats the workpiece locally to the point where it melts, burns, or vaporizes. In some applications, an assist gas helps remove molten or vaporized material from the kerf. The result: clean, burr-free edges—without mechanical tool wear.

How does laser cutting work?

In laser cutting, concentrated laser light—generated and shaped using fundamental principles of laser technology—is directed onto a precise point on the material surface using mirrors and lenses. At this point, the focused laser beam strikes the workpiece with high-energy density, heating it to the point where it melts or vaporizes. The cutting process follows a predefined contour, typically specified digitally using CAD data. Different cutting techniques are selected depending on the material, thickness, and desired outcome.

Structure and workflow of a laser cutting process

The process of laser cutting is based on several core components:

1. Focusing optics: Special lenses or mirrors concentrate the laser beam and align it precisely to the location on the workpiece where processing is to take place.
2. Laser beam: The concentrated beam strikes the material and heats it at a pinpoint location to the extent that it either melts or transitions directly into a gaseous state, similar to processes such as laser drilling.
3. Assist gas: A dedicated gas is supplied to the process to remove molten material from the kerf. It exits together with the laser beam, aligned along the same axis.
4. Striation pattern: The edge formed during cutting shows fine, regular striations. At low cutting speeds, these lines run almost straight in the direction of the beam.
5. Molten zone: Along the intended contour, the material is locally melted by the laser beam, forming a molten zone that is subsequently removed.
6. Cutting front: The gap created by the cutting process is extremely narrow—typically only slightly wider than the focused laser beam itself.
7. Nozzle: The laser beam and assist gas reach the workpiece surface together through a specialized opening known as the cutting nozzle.
8. Cutting direction: By moving either the laser head or the workpiece along a predefined path, the desired cutting contour is generated.

Overview of laser cutting methods

In laser cutting, several methods are differentiated by their underlying physical principles. The most important processes are:

Laser melt cutting

In melt cutting, the laser beam melts the material. An inert assist gas—typically nitrogen, oxygen, argon, or compressed air—expels the molten material from the kerf. This method is particularly suitable for stainless steels, aluminum, and non-ferrous metals because it produces oxide-free cut edges. It is commonly used in sheet metal processing and mechanical engineering.

Laser flame cutting

Flame cutting uses oxygen as an active assist gas. The laser heats the material to its ignition temperature, after which oxidation supports the separation by providing additional reaction heat. This method is especially suitable for unalloyed or low-alloy steels and is preferred for larger material thicknesses.

Laser sublimation cutting

In sublimation cutting, the material is directly vaporized without passing through a molten phase. Because of the minimal thermal impact, the resulting cut edges are extremely fine and clean. This technique is mainly used for thin, sensitive materials such as paper, wood, textiles, or technical films.

Laser fine cutting

Fine cutting is a high-precision variant of laser cutting. It is used when very tight tolerances and micrometer-accurate contours are required, for example, in cutting and routing of PCBs or electronics manufacturing and power electronics. Short-pulse or ultrashort-pulse lasers are often used for this purpose.

Advantages of laser cutting

Laser cutting offers a range of technical and economic advantages. The method enables extremely precise cuts with minimal material loss and clean edges. In most cases, no post-processing is required. Because the laser beam operates without physical contact, there is no mechanical tool wear.

Even complex geometries and delicate contours can be produced with high precision. Thanks to digital control via CAD or CNC systems, laser cutting is equally suitable for prototypes, small series, and high-volume production. Its high repeatability and ease of automation make it especially attractive for modern manufacturing processes.

Which materials can be cut with a laser?

Laser cutting is a highly versatile process in laser processing and is also used in semiconductor technology for precise wafer and component processing. It is suitable for metals such as steel, stainless steel, aluminum, copper, and brass, as well as non-metals including wood, acrylic glass, textiles, plastics, ceramics, and paper. The choice of material depends on the specific laser cutting method used and the desired result.

Factors influencing the laser cutting process

The laser cutting process depends on a finely tuned interaction of various influencing factors. Critical are not only the properties of the material being processed but also the laser power, which determines how quickly and how deeply a material can be cut, and the focal position, which dictates whether the kerf will be clean and uniform. Cutting speed also plays a major role: too fast and the cut remains incomplete; too slow and unnecessary heat is introduced into the material.

In addition, the type and pressure of the assist gas influence the outcome, as they directly affect edge quality, oxidation, and overall process stability.

Hazardous substances and occupational safety in laser cutting

During laser cutting, different emissions may be generated depending on the material and process conditions. Effective occupational safety measures are therefore essential.

Generation of hazardous substances

During the cutting process, various harmful substances can be released depending on the material and its coating. These include fumes, ultrafine particles, aerosols, and gases such as nitrogen oxides or ozone. Cutting plastics, painted surfaces, or coated materials can produce vapors that require specific safety precautions.

Technical safety measures

A key component of occupational safety is proper extraction and filtration technology. These systems remove emissions directly at their source and prevent them from spreading into the workspace. In addition, the cutting system should be operated in a well-ventilated area to avoid harmful concentrations in the air.

Personal protective equipment

Depending on the laser cutting method and the material being processed, personal protective equipment may be required. This includes laser safety goggles that protect against direct and reflected laser light. For certain applications, respiratory protection may also be necessary—especially when local exhaust ventilation is insufficient.

Legal requirements and responsibility

The operation of laser cutting systems in Germany is subject to various regulations, such as the Optical Radiation Protection Ordinance (OStrV) and the Technical Rules for Hazardous Substances (TRGS). Employers are required to carry out risk assessments, instruct employees, and implement appropriate safety measures. Regular training and documented safety procedures are therefore essential components of responsible system operation.

In summary: laser cutting

Laser cutting is a well-established separation method in industrial manufacturing. It can be used in a wide range of laser material processing applications and combines high precision with fully digital control. The overall process quality largely depends on the chosen cutting method and the parameters applied.