3D laser marking is a key technology in industrial marking. It enables the precise and permanent marking of workpieces with complex geometries – contact-free, efficient, and automatable. For manufacturers in industries such as automotive, medical technology, and aerospace, it is a central tool for product traceability and customization.

In 3D laser marking, a focused laser beam is directed onto the surface, where it creates markings by removing material, annealing, or color changes. Unlike many traditional marking methods, the process is not limited to the XY plane as the focus position can be adjusted dynamically. This means that even curved, sloping, or stepped surfaces can be marked evenly and with excellent legibility.

At the core of the technology is a laser system that uses highly dynamic scanner mirrors and dynamically adjustable optics or mechanics to precisely position the laser beam in three-dimensional space.

• The laser beam is directed onto the workpiece by a beam deflection unit with a mirror and focusing lens.
• An additional Z-axis ensures dynamic focus adjustment so that the distance to the surface always remains optimal.
• Intelligent software compensates for distortions, calculates correction files, and ensures that the marking remains uniform even on curved surfaces.
• The surface is heated or ablated locally, depending on the desired marking effect – from annealing and engraving to chemically induced color change.

In 3D laser marking, dynamic Z-movement is crucial for precisely adjusting the focus point of the laser beam in depth, thereby compensating for differences in height or curved surfaces. There are various technical methods for implementing this, which differ in terms of design, speed, precision, and integration effort:

Mechanical movement of the scanning system or component

In this classic implementation, the entire scanning system or component is moved precisely in the direction of the optical axis by a linear motor. This allows the focus to be adjusted exactly to the topography of the workpiece. The method is robust and well established, but comparatively slow and therefore primarily suitable for applications with moderate speed requirements.

Optical focus shift using a linear motor

Here, dynamic focus shift is achieved by axially shifting one or more optical elements—such as a collimating or focusing lens—using a precise linear drive. By specifically changing the beam path in front of the F-theta lens, the position of the focal point can be adjusted along the Z-axis.

This method is often used in modular systems where the actual beam deflection takes place in a fixed XY scanner, while the focus adjustment is performed in front of it in the beam guide. It offers high optical quality and can be easily integrated into existing systems. The range of motion is large, but the response time is usually slower than with voice coil or liquid lens systems due to the mechanical movement. This solution is therefore ideal for processes with variable component heights but moderate dynamic requirements.

Voice coil-based optical focus adjustment

In Voice coil actuators, a coil is located in a permanent magnetic field and, When current flows, it generates a force that is proportional to the current. This force moves the focus lens along the optical axis – quickly, precisely, and with virtually no friction. Since no mechanical contact surfaces are required, the system operates with low wear and very short response times in the range of a few milliseconds.

Voice coil systems are ideal for dynamic labeling processes with frequently changing focus positions. However, the travel range is limited, which is why they are usually used in combination with optically compact systems.

Deformable liquid lenses (Tunable Liquid Lens)

The use of deformable liquid lenses offers a very compact solution for dynamic focus adjustment. These systems do not change their focal length through mechanical movement, but rather by applying an electrical voltage. This allows the focus of the laser to be shifted within milliseconds without having to move any mechanical components.

Liquid lenses are particularly suitable for space-critical applications and can be easily integrated into compact laser modules. They offer high focus dynamics with low weight and volume. However, due to aberrations, limited aperture size, and limited suitability for high-power lasers, they are mostly used in systems with moderate optical power, for example in the marking of plastics or in mobile laser systems.

Materials such as titanium and nickel alloys place high demands on marking technology. In jet engines or on turbine blades, 3D laser marking ensures abrasion- and temperature-resistant markings. Serial numbers and QR codes can also be applied reliably.

3D laser marking offers a number of technical and economic advantages over conventional marking methods:

• Processing complex geometries: Curved, inclined, or multidimensional surfaces can be marked evenly without mechanical repositioning.
• Maximum precision: Dynamic focus tracking ensures consistent marking quality even with differences in height.
• Versatile effects: Material removal, color change, or annealing —the desired type of marking can be precisely controlled.
• Material diversity: Metals, plastics, ceramics, or glass – 3D laser marking is suitable for a wide variety of materials.
• Durability: The markings are abrasion-resistant, chemically resistant, and insensitive to environmental influences.
• Efficiency and low maintenance: Non-contact processing without tool changes or wear reduces downtime and maintenance costs.
• Automation: The combination of a 3D scanner, focus adjustment, and intelligent software allows for complete process integration.
• Sustainability: No ink, chemicals, or labels are used – the process is resource-efficient and environmentally friendly.

3D laser marking opens up new possibilities for the reliable marking of complex shaped products. The optimal combination of beam deflection, Z-axis technology, and intelligent control is crucial for stable and economical process control.

As an experienced integration partner, RAYLASE not only supplies high-performance deflection units, but also considers the entire processing process. Our components enable precise and efficient implementation of individual 3D marking requirements – whether with a mechanical Z-axis, adaptive optics, or high-end scanning solutions.

Would you like to learn more about our solutions for 3D laser marking or discuss a specific project?

Then talk to our experts – we will be happy to advise you and assist you in selecting, simulating, and integrating the optimal configuration for your application.