Laser Marking Technology Comparison: A Detailed Look at Fiber, CO2, UV, and Green Lasers
If you have ever researched Laser Marking machines, you have likely encountered these four terms:Fiber Laser, CO2 Laser, UV Laser, and Green Laser. You may have seen these names repeatedly, yet the fundamental principles behind laser marking-and how to choose the right machine-can still feel unclear.
Laser marking is an irreversible process. Choosing the wrong equipment costs more than time and money spent on the purchase-it can damage products or workpieces and cause costly production delays. This article provides a detailed breakdown of how each laser type works and where it performs best, so you can gain a clearer understanding of your specific laser marking needs. If you already grasp the basics and simply want to select a machine, please refer to our companion article: "Laser Marking Machine Selection Guide: Three Steps to Choosing the Right Equipment."
Ultimately, the distinction between Fiber, CO2, UV, and Green laser marking machines comes down to a single factor: the laser wavelength.
Think of the laser wavelength as the pattern of a key's teeth, and the material's absorption rate as the shape of the keyhole.
If the key fits, the light energy is absorbed and marking occurs; if it does not, the light is reflected and no mark is made.
Choosing a laser is essentially a matter of fitting the right key to a specific material.
These four laser types represent four different keys. Arranged from longest to shortest wavelength, they are:
CO2 (10.6 μm) > Fiber (1064 nm) > Green (532 nm) > UV (355 nm)
Wavelength determines not only whether the "key" fits the "lock" but also the method of "unlocking"-some lasers operate via ablation (thermal processing), while others function by breaking chemical bonds (cold processing).
Fiber lasers and CO2 lasers utilize thermal processing: the laser beam strikes the material, causing the surface temperature to spike rapidly, which leads to vaporization or carbonization. It is akin to branding wood with a red-hot iron; heat is the driving force.
UV lasers and Green lasers employ cold processing: photon energy is high enough to directly break molecular bonds and induce color changes, while generating virtually no heat. It is like writing on paper with a special pen; chemical reactions, rather than heat, drive the process.
Why does the distinction between thermal and cold processing matter?
Because thermal processing can damage heat-sensitive materials. Processing thin-walled plastic parts with a fiber laser causes deformation, whereas switching to a UV laser results in negligible thermal impact, keeping the part intact.
The trade-off: cold processing is slower and achieves shallower processing depths. Cold processing is like a scalpel, while thermal processing is like a sledgehammer-each is suited to different applications.
Next, let's analyze each of the four laser types.
1. Fiber Laser - The King of Metal Marking
Wavelength: 1064 nm | Thermal Processing
This wavelength is highly compatible with metal materials. Whether it is stainless steel, carbon steel, aluminum alloy, or titanium alloy, these materials efficiently absorb fiber laser light, resulting in clear, deep marks.
However, there is a significant limitation: wood, transparent glass, and other organic materials have extremely low absorption rates at the 1064 nm wavelength. Irradiating wood with a fiber laser produces almost no reaction.
While fiber lasers are the preferred choice for marking general metals, there is an often-overlooked issue: metals such as gold, silver, and copper exhibit high reflectivity at 1064 nm. Fiber lasers often struggle when processing highly reflective metals like copper-resulting in low efficiency and potential damage to the laser source itself. We will revisit this point later when discussing green lasers.
The true advantage of fiber lasers lies not only in marking quality but also in hardware durability: an all-solid-state design, a maintenance-free lifespan exceeding 100,000 hours, air cooling, and extremely low energy consumption. Once installed on the factory floor, a fiber laser can operate for nearly a decade with minimal maintenance.
Regarding power: drawing on years of customer service experience, Daina offers fiber laser marking machines in 20W, 30W, 60W, and 100W configurations to meet diverse user needs regarding the balance between speed and precision.
Suitable materials: Stainless steel, carbon steel, aluminum alloys, titanium alloys, rigid ABS, epoxy resins, ceramics
Typical applications: Plastic piping, metal profiles, hardware nameplates, automotive part serial numbers, medical devices, electronic product housings, bearing codes
2. CO2 Lasers - Experts in Organic Material Processing
Wavelength: 10.6 μm | Thermal Processing
The wavelength characteristics of CO2 lasers perfectly complement those of fiber lasers: while metals almost entirely reflect this wavelength, non-metallic organic materials absorb it strongly. CO2 lasers can easily mark a wide range of materials, including wood, leather, paper, acrylic, glass, and rubber.
Most date codes found on beverage bottles in supermarkets are marked using CO2 lasers. They are the industry standard for production lines involving food packaging, pharmaceutical packaging, and paper label barcodes.
Entry-level CO2 laser systems are priced similarly to fiber lasers-and lower than UV lasers-making them the top choice for small businesses with limited budgets that primarily process non-metallic materials.
It is worth noting that CO2 lasers utilize gas laser tubes; the tube may require replacement after approximately 30,000 hours of use.
Suitable materials: Wood, leather, paper, acrylic, glass, rubber, textiles, ABS, PC, PET bottles
Typical applications: Date codes on bottled water and food/beverage packaging, pharmaceutical batch numbers, wood engraving, leather marking, barcodes on paper labels
3. UV Lasers - The Benchmark for Precision in "Cold Marking"
Wavelength: 355 nm | Cold Processing (Photochemical Reaction)
Among these four laser types, UV lasers have the shortest wavelength and the highest photon energy. Their photon energy is sufficient to directly break molecular bonds and induce color changes while generating virtually no heat.
This is what the industry calls "cold marking"-no charring, no deformation, and a heat-affected zone of nearly zero.
What does this mean in practical terms? You can mark QR codes on 0.1 mm thick flexible printed circuits (FPCs) without burning through them or causing short circuits; create high-contrast black marks on white plastic without scorching the material; and engrave thin glass without causing it to crack.
The minimum line width can reach 0.01 mm-the highest precision among the four laser types.
What is the trade-off? Slower speeds and higher costs. UV marking speeds are significantly lower than those of fiber lasers, and the cost per unit of power is the highest among these laser categories.
Therefore, UV lasers are not general-purpose devices but specialized tools designed for heat-sensitive, ultra-fine, and high-standard applications.
Suitable materials: Glass, ceramics, white/heat-sensitive plastics, FPCs, PI films, IC chips, silicon wafers, pharmaceutical blister packs
Typical applications: Microelectronics marking, mobile phone glass screens, QR codes, pharmaceutical packaging, high-end cosmetics, medical devices
4. Green Lasers - The Nemesis of Highly Reflective Metals
Wavelength: 532 nm | Visible Green Light | Cold Processing (Photochemical Effect)
Remember the challenge mentioned earlier? Fiber lasers often struggle when processing highly reflective metals like gold, silver, and copper, because these metals reflect 1064 nm laser light directly back. Green lasers effectively address this limitation.
At a wavelength of 532 nm, the absorption rates of gold, silver, and copper are significantly higher than at 1064 nm. While fiber lasers often yield poor results when marking gold jewelry, green lasers produce instant, high-contrast, and finely detailed markings without damaging the substrate.
Green lasers also offer cold processing capabilities, resulting in a much smaller heat-affected zone compared to fiber lasers. They excel in marking applications for PCBs, semiconductor wafers, and silicon wafers-making them the preferred choice, particularly for marking traceability codes on silicon wafers.
However, green lasers serve a specialized purpose. Rather than being general-purpose equipment, they are specialized tools designed for highly reflective metals and semiconductor materials. Compared to fiber or CO2 lasers, they have a narrower application range and higher equipment costs.
Suitable materials: Gold, silver, copper, anodized aluminum, silicon wafers, semiconductor wafers, PCBs, jade, specialty plastics
Typical applications: Jewelry engraving, semiconductor wafer traceability, precision PCB marking, jade engraving, anodized aluminum marking
Four Laser Types at a Glance
| Dimension | Fiber | CO2 | UV | Green |
| Wavelength | 1064 nm | 10.6 μm | 355 nm | 532 nm |
| Processing Method | Thermal | Thermal | Cold | Cold |
| Best Materials | Metals / hard plastics | Non-metal organics | Heat-sensitive materials / glass | Highly reflective metals / semiconductors |
| Speed | Very fast | Fast | Medium | Medium |
| Precision | High | Medium | Extremely high | High |
| Typical Power | 20–100W | 30–100W | 3–25W | 3–20W |
| Lifespan | 100,000+ hours | ~30,000 hours | ~25,000 hours | ~25,000 hours |
| Cost | Medium | Medium | High | High |
The One-Sentence Summary
There is no best laser-only the right wavelength.
Brief Direction:
Metal → Fiber.
Non-metal → CO2.
Heat-sensitive → UV.
Reflective metal → Green.
Ready to choose? Read the companion article: "Laser Marking Machine Selection Guide: Three Steps to Choosing the Right Equipment."