Five Reasons for the Uneven Marking Effect of Fiber Laser Marking Machines

At present, people use laser marking technology in production. Such as machinery manufacturing, medical equipment, watch glasses, craft gifts and many other industries. The operator can make the desired pattern through laser marking technology. When marking patterns, processors may often encounter such a question: “Why is the marking effect of the fiber laser marking machine uneven?”

1. Defocus mark on a certain range of materials

Each focusing lens has a corresponding range of focal depths. Out-of-focus operations will easily lead to the target beyond the depth of focus range. This is more likely to cause uneven effects. Therefore, the operator must consider the laser energy when selecting a method for off-focus marking.

2. The spot of the laser is blocked

During the actual operation, the operator may not correctly adjust the position of the laser output head, fixing fixture and galvanometer. Therefore, when the laser passes through the galvanometer, part of the light spot will be blocked. The spot after focusing by the field lens is non-circular. This can lead to uneven results.
When the laser beam passes through the damaged area of the lens, it does not reflect well. Therefore, after the laser beam passes through the damaged area of the lens, the laser energy changes. The laser energy that ultimately acts on the material is also different. Finally, this can make the marks uneven.

3. Thermal Lens Phenomenon

When laser light passes through an optical lens (refracted, reflected), it causes the lens to heat up and cause slight deformation. This deformation increases the focus of the laser and shortens the focal length. If the operator holds the machine and turns on the laser for some time, the laser fluence on the material changes due to thermal lensing. Therefore, this results in an uneven marking effect.

4. The level of the machine table is not adjusted properly

The operator should place the galvanometer or field lens parallel to the processing table before operation. If the two are not horizontal, the distance between the laser beam and the object to be processed will be inconsistent after passing through the field lens. Finally, the energy of the laser falling on the workpiece will have an inconsistent energy density. At this time, the processing effect of the material will be uneven.

5. Material Properties

Materials are sensitive to laser energy. Usually under the same material, the laser energy reaches a certain material damage threshold. When the thickness of the material coating is different, or some other chemical processes are not uniform enough, it will also cause unevenness in the effect of laser marking.


Machines are like people. With the increase in use time and the wear and tear of parts, the machine will have various failures. The same is true for laser marking machines, and the marking results may be uneven. Therefore, in the process of use, the staff should regularly test and adjust the machine. And before buying a laser marking machine, buyers should choose the configuration of the machine according to the processing needs. Doing so ensures the best performance of the machine.

Welcome to contact us for more details.

Working Video

Working Video


If you want to learn more about it, welcome to contact us by email or by whatsapp/wechat.


Whatsapp: 0086 18254116182