CO2 vs Fiber vs UV Lasers – What’s the Difference?

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All types of lasers are unique, each will suit different materials and tasks. In fact, even within one type of laser source technology, there are variations in quality, type, power, and versatility.

So how do you know which one to use?

To make it digestible, I’m going to break it down into three main types of lasers. They are all capable of marking or engraving to some extent, but not all of them will work effectively, so let’s take a look at the pros and cons of each.

Further down the page there is a quick reference table to use, but be aware that it is generic and there are caveats for each material.

UV lasers

UV lasers work a little differently from their CO2 or fiber based siblings because they don’t damage the surface of surrounding materials, using a much weaker form of marking. This makes it the best of the bunch when it comes to “marking”, suitable for everything from fruit and glass to Teflon, diamond, silicone, plastic and precious metals. You can really mark almost anything with a UV laser! 

How do UV laser marking systems work?

Operating at 355nm, UV lasers have a much shorter wavelength than other technologies here. Using a process called “cold processing,” UV lasers emit high-energy photons in the ultraviolet spectrum that break chemical bonds in the material, causing non-thermal damage to the material. This process does not produce thermal deformation (thermal damage) on the inner layers and areas close to the target area. 

The wavelength of a UV laser is one-third of standard wavelength lasers, therefore often referred to as third harmonic generation (THG) lasers. This wavelength is achieved by passing a laser of standard wavelength at 1064nm through a nonlinear crystal, reducing it to 532nm, and then passing it through another crystal, further reducing its length. wave, up to 355 nm working.

In summary, the UV marking process is extremely fine and controlled, making it ideal for delicate or precise jobs. However, due to the process used by this technology, a UV Laser Marking System is not normally suitable for engraving or cutting. 

Advantages
  • Suitable for marking the widest range of materials
  • Ideal for delicate and precise work
  • Very low power requirements
  • Long lasting and maintenance free period
The inconvenients
  • Not very suitable for cutting or engraving
  • More expensive than CO2

Fiber laser

Fiber lasers are the ideal option for part marking, engraving and especially metal. They are very well established in many industries and are often found on manufacturing lines, workshops and more, all over the world.

With most fiber laser modules having more than 100,000 hours of operation before any maintenance, they are exceptionally reliable (however, other components of a laser marking system may require regular maintenance). In addition, as a fiber laser engraver can be easily adjusted to achieve greater depth, they are very flexible and easy to use.

Operating at the wavelength of 1064 nm, they are very well suited to metals, but can also operate on a much wider range of materials. This is why they are the most common choice for traceability marks such as barcodes, QR codes and text. Moreover, their use for other graphics on items such as personalized items, light switches, phones, jewelry is becoming more popular day by day. 

How do fiber laser engravers work?

When a fiber laser encounters an object, it evaporates the surface material to expose deeper material, essentially “sculpted” by chemical and physical changes. These changes are caused by light energy (photons) reacting in the target area.

Fiber lasers have high electro-optical conversion efficiency, which means in simple terms that they convert more energy into light (compared to CO2). In reality, this means that fiber laser systems require less power to make a material, resulting in low power consumption for a fiber laser marking machine. 

Types of fiber lasers

There are two common types of fiber laser that you will find offered by manufacturers, we offer both types depending on the users budget. The main difference between these types of technology is the variety of pulse width and frequency.

Q switch

Arguably the most common type of fiber laser source, it’s also the cheapest. They are generally not as efficient and do not have such a wide range of pulse modulations. In turn, this means that they are less flexible than a MOPA laser and are much more prone to warping different materials.

MOPA

A MOPA laser is much more flexible, with a range of pulse width and frequency settings available, it can suit more materials, and is less prone to creating unwanted distortions when configured correctly. However, MOPA laser sources are quite varied in themselves, with the quality and versatility of modulation differing from manufacturer to manufacturer. They are also more expensive than Q-Switched systems. 

Advantages
  • Versatile range of applications
  • Long lasting and maintenance free period
  • Fast engraving speed
The inconvenients
  • More expensive than CO2 lasers
  • Less versatile for marking than UV
  • Not suitable for some organic materials (wood, glass, fabric, etc.)

CO2 lasers

CO2 laser cutters and engravers are excellent for organic materials like rubber, wood, paper, glass and ceramics. They are also the go-to choice for cutting acrylic and other plastics.

CO2 systems are among the most common types of laser used for industrial engraving and cutting. Smaller, lower wattage units are most commonly used by hobbyists due to their low cost (but they also have a much shorter lifespan).

How do they work?

Using CO2 gas in a sealed tube, acting as a laser medium, they operate at the wavelength of 10,600 nm. Unlike other technologies here, CO2 lasers are generally available in a plotter format, but they are also available in a sealed unit.

FORMATS

Plotter (laser plotter)

A plotter system is a motion system that typically contains multiple steppers or servos, rails, and belts. There is a series of 3 or 4 mirrors which deliver the beam by deflection to a focusing carriage which usually contains a single-layered plano-convex lens. 

During operation, the lens moves over the work area, which is usually large and rectangular in shape, to deliver the focused laser to the workpiece.

Sealed (Galvo Laser)

This is a sealed unit, usually containing 2 mirrors attached to galvanometers. The beam is focused through a fixed lens known as the F-Theta lens which has a wavelength of 1 µm. The working area is constrained by the characteristics of the lens and is generally quite small and circular in shape. Technically, this is called a deflection laser.

TECHNOLOGIES

CO2 DC Lasers

These are the most common types of lasers found in manufacturers’ systems because they are relatively inexpensive. Although efficient, they are slower than RF systems. In addition, the laser power will gradually decrease and their lifespan will be shorter (although manufacturers can quote 10,000 hours, this is only when used at low power settings).

CO2 RF laser systems

RF systems can be more expensive, but the benefits outweigh the cost. We opt for this technology in our machines so that they can operate at much higher speeds, in fact our systems are generally twice as fast as those of other manufacturers. Unlike direct current, the output power of the laser will remain virtually constant over its lifetime. In addition, the quality of beam delivery and a life expectancy can exceed 20,000 hours (almost 12 years of shift work), so this is a no-brainer when looking at CO2 laser cutters.

Advantages
  • Can mark organic materials and glass
  • Good engraving speeds
  • Lower cost (excluding galvo lasers)
The inconvenients
  • Shorter lifespan
  • Difficulties in marking metals
  • Less precise than other technologies