When large scan fields are processed, speed is only one part of the equation. The beam must also cover the field uniformly, while position, spot size and energy distribution remain predictable from the centre to the edge.

MOEWE dual-polygon optics distributes beam deflection across two coordinated polygon stages. This creates additional degrees of freedom for the optical design, control system and calibration. When properly designed, the approach can reduce field-dependent distortions and improve process consistency across the complete scan field.

The challenge: large scan fields are not automatically homogeneous

With a single deflection element, the geometric conditions change with the scan angle. At the edge of the field, the beam follows a different path through the optics than it does at the centre. The angle of incidence, effective spot size, line spacing and energy density can change at the same time.

For industrial applications, this means that a part may be processed differently in the centre and at the edge even though the nominal process parameters are identical. Typical effects include:

• deviating feature dimensions or contours at the field edge,
• different line widths and overlaps,
• variations in energy input,
• higher requirements for calibration and correction models.

How MOEWE dual-polygon optics works

Instead of concentrating the complete deflection on a single polygon stage, the dual-polygon design coordinates two deflection stages. Depending on the system architecture, the two stages handle different components of the beam deflection or work together in a coordinated combination.

The objective is not simply to add more optics. It is to distribute the geometry more effectively: each stage represents a smaller or more controlled part of the overall movement. The resulting field geometry can therefore be modelled more precisely and matched to the application.

Why the scan-field distortion is reduced

1. Lower angular load per polygon stage: Distributing the required deflection across two stages can reduce extreme angle changes at each stage. This creates more favourable conditions for the subsequent focusing optics.
2. More degrees of freedom for correction: The spot position can be described through the coordinated movement of both stages. Optics, control and calibration can therefore be matched more closely to the actual field geometry.
3. More manageable field edges: The most critical deviations often occur where the beam is deflected far from the optical axis. Distributed deflection can reduce this sensitivity and narrow the difference between the field centre and field edge.
4. More stable process conditions: A more uniform beam path supports a consistent spot geometry and energy density. This can improve repeatability in marking, microstructuring and selected laser-processing applications.

Single polygon and dual-polygon optics compared

What this means for industrial processes

For applications involving large areas and demanding throughput and uniformity requirements, dual-polygon optics can provide several benefits:

• more consistent feature dimensions across the scan field,
• more uniform energy distribution when the system is properly designed,
• improved repeatability in marking and microstructuring,
• more freedom when coordinating scan strategy, focus and calibration.

The actual benefit always depends on the combination of wavelength, laser power, beam diameter, scan field, focal geometry, polygon speed, control system and material.

Optics alone does not determine the result

Dual-polygon optics does not replace careful system design. Reliable results require the optical properties to work together with the control system and a suitable calibration method. Scan direction, acceleration profiles, pulse parameters and the thermal properties of the material also influence the achievable homogeneity.

The relevant question is therefore not only, “How large is the scan field?” The key question is which spot quality, speed, accuracy and energy distribution the process requires at every position in that field.

Conclusion

MOEWE dual-polygon optics reduces scan-field distortions by distributing beam deflection across two coordinated polygon stages. This creates additional degrees of freedom for geometry, control and calibration. Edge deviations can be managed more effectively, supporting more uniform process conditions across large scan fields.

Frequently asked questions

Does dual-polygon optics eliminate every scan-field distortion?

No. It creates better conditions for controlling the field geometry, but it cannot replace precise design, calibration and process optimisation.

Which applications can benefit from the approach?

It is particularly relevant for large areas that must be processed quickly while maintaining uniformity and repeatability, for example in marking, microstructuring or selected laser-processing applications.

Which data is needed for an evaluation?

Useful information includes wavelength, laser power, beam diameter, target spot size, scan field, processing speed, material and process objective.

Would you like to evaluate your scan field?

MOEWE Optics supports the evaluation of suitable scanner and optical configurations. Share your key process data and we can assess whether dual-polygon optics is a good fit for your application.

PM10, PM30 or PM Unit? The best scanner solution depends on more than the desired speed. Scan field, spot size, laser parameters, material, cycle time and machine integration all influence the right choice.

This guide explains the questions that help with selection and when each MOEWE scanner typically belongs on the shortlist. The final configuration should always be evaluated against the real process data.

The three key selection questions

1. How large is the required scan field? Field size and target resolution determine the optical and mechanical design.
2. How fast must the process be? Marking time, line speed, acceleration and repetition rate work together.
3. How much adaptation does the scanner need? A standard integration has different requirements from a customised OEM solution.

PM10: compact and focused

PM10 is a natural choice when a compact scanner solution is needed for clearly defined tasks. It is particularly relevant when size, straightforward integration and a balanced combination of speed and precision are important.

Typical use cases include compact marking and structuring tasks, small to medium working fields or machines where installation space is limited. The planned scan field, target spot size and process speed must, of course, match the optical design.

Consider PM10 when:

• a compact standard solution is required,
• the scan field is manageable and clearly defined,
• installation space and integration effort are important factors,
• the process needs a good balance between dynamics and precision.

PM30: more reach and throughput

PM30 typically comes into consideration when a larger working field or higher throughput is central to the application. Larger parts and productive series processes require field coverage, spot quality, speed and process homogeneity to be considered together.

A larger scan field is not automatically the better solution. As field size increases, the requirements for optics, calibration and process control also increase. PM30 is therefore particularly interesting when the application genuinely needs the additional reach and the process parameters can be designed around it.

Consider PM30 when:

• larger areas or parts need to be processed,
• short cycle times and high throughput are decisive,
• field coverage matters more than the smallest possible housing,
• optics, control and calibration can be designed as one system.

PM Unit: when integration defines the solution

PM Unit is the right starting point when an application goes beyond a typical standard configuration. The focus is then not only on scanner size and speed, but on how the scanner becomes part of the complete machine or production line.

This can be relevant when special mechanical interfaces, a specific beam path, defined installation requirements, customised control or a coordinated multi-component solution is needed. PM Unit should therefore be included early in the system planning process.

Consider PM Unit when:

• a customised OEM or machine integration is planned,
• standard dimensions or interfaces are not sufficient,
• optics, mechanics, electronics and software must be coordinated,
• the solution should be optimised for a specific process rather than a generic data sheet.

PM10, PM30 or PM Unit compared

Which data should be available before selection?

The more precise the starting data, the faster the right configuration can be identified. Useful information includes:

• laser wavelength and available power,
• required scan field and working distance,
• target spot size and positioning accuracy,
• line speed, cycle time and repetition rate,
• material, geometry and processing task,
• installation space, interfaces and environmental conditions.

The short decision guide

PM10 is a good starting point for compact and clearly defined applications. PM30 should be evaluated when a larger field or more throughput is required. PM Unit is useful when system integration, interfaces or process requirements call for an individual design.

Selection should not be based on one specification in isolation. The interaction between scan field, spot, speed, laser and machine reveals which scanner provides the best solution in the real process.

Frequently asked questions

Is PM30 always better than PM10?

No. A larger or faster system is only beneficial when the application needs those characteristics. For compact fields, a smaller and appropriately configured solution may integrate better.

When should PM Unit be planned?

As early as possible when special interfaces, beam paths, installation constraints or OEM integration are foreseeable. This allows optics, mechanics and control to be designed together.

Can MOEWE support the selection using sample data?

Yes. Information about the material, laser, scan field, spot size, speed and process objective allows the appropriate scanner class to be evaluated in a targeted way.

Not sure which scanner is right?

Share your key process data with us. MOEWE Optics can help assess whether PM10, PM30 or PM Unit is the right starting point for your application.

Polygon scanners and galvanometer scanners are not competing technologies in every application. In many laser processes, they complement each other: the polygon scanner provides high-speed line deflection, while the galvo adds flexible positioning within the working field.

What a galvo scanner does best

Galvo scanners are a flexible solution for two-dimensional laser processing. They can position the beam freely within the available field and are well suited to contours, variable geometries and applications that require frequent changes in the scan path.

The decisive advantages are flexibility, simple adaptation to different geometries and straightforward integration into many laser systems. For smaller and medium-sized working fields, a galvo solution is often the right starting point.

Where a polygon scanner has its strengths

A polygon scanner deflects the laser beam at very high speed along a scan line. This makes it particularly interesting for large-area processing, continuous material handling and processes in which the available laser power should be used efficiently.

MOEWE polygon scanners are designed for high-speed beam deflection and real-time control. Depending on the configuration and optics, they support applications such as marking, microstructuring, surface cleaning, drilling, cutting and engraving. Bitmap and line-processing modes also make it possible to process digital patterns and parameterised scan jobs.

Why combine a polygon scanner with a galvo?

The combination uses the strengths of both systems. The polygon scanner generates the fast scan lines, while the digitally controlled galvo shifts the position of these lines. This creates a two-dimensional processing field without having to move the complete scanner mechanically for every line.

The result can be a high-throughput process with flexible positioning. Depending on the application, additional axes, rotary units or roll-to-roll transport can be integrated as well. This is especially useful when a moving substrate must be processed continuously or when a large area needs to be covered quickly.

Typical applications

• Large-area laser marking and surface structuring
• Continuous processing of films, foils or other moving substrates
• Laser cleaning, cutting or drilling of thin materials
• Engraving and parameterised 2D or 2.5D processing
• Processes that combine high scan speed with changing geometries

When does the combination make sense?

A polygon scanner and a galvo are worth combining when both speed and flexible positioning are important. Typical indicators are:

• The process must cover a large area within a short cycle time.
• The workpiece or substrate is moving continuously.
• Scan lines, contours or processing windows need to change during the process.
• The system benefits from synchronisation between laser, scanner and external axes.
• The optics, aperture, focal length and laser parameters are compatible with the required process window.

What should be clarified during system design?

The right solution depends on more than the nominal scan speed. Working-field size, focal length, laser wavelength and power, material behaviour, required resolution, duty cycle and the motion of the workpiece all influence the design.

It is also important to define the data path and synchronisation at an early stage. Real-time processing, encoder feedback and the selected interface determine how reliably the scanner, laser and motion system work together.

Conclusion

A galvo scanner is the flexible choice for freely positioning a laser beam. A polygon scanner is the high-speed specialist for line-based processing and large-area throughput. Combining both can therefore be useful wherever a process needs high productivity without giving up flexible positioning.

The best configuration is always application-specific. MOEWE supports the evaluation of scanner concept, optics, control and integration for the intended laser process.