Difference Between UV Laser and Fiber Laser Engraving Machines

Definition of UV Laser

A UV laser is a laser that uses ultraviolet light to mark materials through heat absorption.

First, a 1064 nm laser is converted into a 355 nm laser through two crystals. Then, the 355 nm beam then breaks down bonds directly using a photolytic degradation process. This process is known as “cold marking” because it does not burn surface areas and uses minimal heat stress. KEYENCE’s UV laser marking machine is the 3-Axis UV Laser MD-U Series.

Definition of Fiber Laser

A fiber laser is a laser with an infrared laser with a wavelength of 1090 nm. The fiber laser uses heat to cut, engrave, mark, etch, and remove burr. KEYENCE’s fiber laser marking machine is the 3-Axis Fiber Laser MD-F Series.

Benefits of UV Laser

Damage-Free Marks

UV lasers break down bonds directly, so minimal heat stress is used when marking. Because of this, no residue of burrs or yellow tinting is left over on the marked materials.

Easy Marking on Sensitive Materials

Since UV lasers do not rely on heat marking and use absorption, these lasers can mark materials that are heat sensitive and may be damaged by high-powered lasers.
Heat-sensitive materials that a UV laser can mark are:

  • Cartons
  • Rubber
  • Resin
  • Bag film

Advantages of UV Laser

High Absorption Rate

A UV laser has a 355 nm laser with an incredibly high absorption rate. Meaning that even with materials that have high melting points, like glass or metal, the UV laser can still mark them without using high power. Additionally, since the absorption rate is so high, the laser does not damage the material.

Small Spot Diameter

The MD-U Series’ UV wavelength is ⅓ of the size of a standard laser wavelength. Because of this, the UV laser only marks precisely on the spot it needs to. Therefore, there is no swelling across the material that could cause deformation.

Additionally, the small spot diameter allows for marking on small products with intricate detailing. Some examples are 2D codes, plastic tubes, gas meter casings, and in-vehicle plastic parts.

Benefits of Fiber Laser

Increased Efficiency with Output

Fiber lasers are known for their high output making for quicker production times. The MD-F series has two choices of outputs, 30W and 50W. With these outputs, the fiber laser can mark, cut, engrave, and anneal materials fast.

High Contrast Metal Marking

For metals like iron that are not highly reflective, the fiber laser can create high contrast marks. Other lasers that have high absorption rates cannot achieve the same effect.

Advantages of Fiber Laser

Scratch Control

Fiber lasers are a good choice for cutting materials because of their high output. The 3-Axis Fiber Laser MD-F Series has scratch control which allows for clean cuts. The cutting process moves the fiber laser beam back and forth across a short distance. Since the fiber laser beam moves across a short distance, the energy is focused. This results in speedy processing time and clean cuts.

Wobble Control

The MD-F fiber laser achieves high-quality annealing with wobble control. The Wobble control makes the laser move in a circular pattern rather than overlapping single lines. The circular pattern ensures thick characters and concentrated energy.

Deep Engraving Control

The high output of 50W not only marks fast, but it can engrave deeply. The output's high heat digs deep into materials. With the deep engraving control of the MD-F, the focal distance varies for each laser pass. Because of this, the maximum energy density is achieved throughout the marking.

Differences Between UV and Fiber Lasers

Type of Laser

From a foundational standpoint, a UV laser vs a fiber laser differ greatly. UV lasers use an ultraviolet laser while fiber lasers use an infrared laser. Additionally, the UV laser is 355 nm while the fiber laser is 1090. Since they have different types of lasers, each laser has a separate process of marking. Fiber lasers use high heat with high output to mark materials while UV lasers use absorption to break down bonds.

UV Laser Applications vs Fiber Laser Applications

A UV laser does not rely on heat for marking, so it can mark heat-sensitive materials without damage. On the other hand, fiber lasers do use heat, so they do not have the capability of marking on heat-sensitive materials without damage. But, fiber lasers may be better for certain metals like iron because of the high output creating high contrast.


When it comes to speed, choosing a UV laser vs a fiber laser depends on how fast you want production to be. Fiber lasers have a high output of 50W while UV lasers have an output of 3W. Because of this, fiber lasers are significantly faster. Fiber lasers are optimal for big production marking, cutting, or engraving projects that need efficiency.

Similarities of Fiber and UV Lasers at KEYENCE

3-Axis Control

The 3-Axis UV Laser MD-U Series and the 3-Axis Fiber Laser MD-F Series at KEYENCE both have 3-Axis control. The 3-Axis control allows for both lasers to mark perfectly on any surface, even 3D surfaces. It works by using an auto-focused focal point rather than a fixed focal point like other conventional lasers. When a material is under the laser, the focal point automatically adjusts for the target area depending on the material's size and height and how it is placed in the production line. Because of this, both the fiber laser and the UV laser can ensure uniform and distortion-free marking.


UV lasers and fiber lasers each have specifications that make them optimal for certain production projects. If your project includes marking heat-sensitive materials or marking on small objects, choosing a UV laser is best. However, if you are looking for a high-speed laser that can achieve clean cuts, engraving, or annealing on metal, you may want to choose a fiber laser.

Whichever you choose, UV laser vs fiber laser, KEYENCE is here to help. At KEYENCE, we have a knowledgeable team that will help you throughout your selection process to operations with on-site operating instructions, along with industry-leading after-sales support.

Related Downloads

MD-F3000 Series 3-Axis Fiber Laser Marker Catalog

Introducing the new MD-F Series, 3-Axis 30W Fiber Laser Marker


Metal Printing Process Instruction Manual

This quick guide introduces the basics of metal marking. Learn why different wavelengths matter and discover the various ways laser light interacts with metal parts.