Fiber Laser Technology: How Fiber Laser Engravers Work

Fiber laser engravers focus a beam of light through a fiber optic cable to make permanent marks on metals and some plastics. Learn everything you need to know about fiber laser technology and machines here!

What Is a Fiber Laser Engraver? 

Fiber laser engravers are used to make permanent marks on metals and some plastics. In the engraving process, a focused beam of light is sent through a fiber optic cable and used to mark the surface of the material. The surface absorbs the laser, melts, and discolors. Fiber laser engravers are also referred to as fiber laser marking machines. They're used extensively by crafters and manufacturers to create custom designs and personalized items and to mark product parts for identification and tracking.

What do fiber markers do? 

Fiber optic lasers are precise machines used for marking, cleaning, and texturing, among other tasks. Fiber laser marking machines are used across all industries, including the aerospace, dental, medical, automotive, jewelry, scientific, and sensor fields. The flexible fiber optic cable allows for extreme precision and fast working speeds.

Manufacturers often use fiber laser markers to identify products — such as car parts or medical devices — so they can be easily traced. However, crafters and small businesses also use fiber laser markers to create unique products. From wedding gifts to promotional items, a fiber laser engraver can be used to make personalized items and artwork from a wide range of different materials.

While fiber laser technology is extremely versatile, it's important to differentiate between a fiber laser engraver and a fiber laser cutter. Fiber laser cutters are far more powerful than fiber laser engravers because they have a more intense and focused laser source. A fiber laser engraver produces a wavelength between 800 and 2,200 nm, while a fiber laser cutting machine operates at a wavelength between 9,000 and 11,000 nm. While it's possible to cut metal with a fiber laser marker, you would need a laser source of around 2,000 watts. A standard DIY fiber laser machine has 20 to 50 watts of power.

How Does a Fiber Laser Work? What is the fiber laser technology?

All lasers have three main components — an energy source, a laser medium, and an optical resonator. The energy source, or pump source, is where a laser gets its energy. The laser medium, also called the gain medium, determines the laser's wavelength. Many different laser media can be used as the base of a laser. The optical resonator, or optical cavity, reflects the light, so it feeds back into the system.

A fiber laser uses a low-maintenance laser source to generate a laser beam that travels through a "doped" fiber optic cable to the beam head. A doped fiber optic cable contains ions from rare earth elements such as ytterbium. Such elements increase the efficiency and performance of the fiber. The beam head contains a beam expander and a lens. This is the part that actually does the marking. 

Laser marking machines expose materials to a low-powered beam. This doesn't affect the properties of the materials but instead uses a process called laser coloration on the surface to create high-contrast markings. Using software such as EzCad, fiber laser markers are able to create elaborate text, pictures, or patterns based on your designs

How fiber laser sources work

The source of a laser beam in a laser fiber machine is the pump source. The pump source consists of laser diodes that convert electricity into light. The diodes contain two semiconductors with opposite electrical charges. When these opposite charges meet, they release a free electron which then emits a photon. These photons build up as electricity travels through the diodes. The photons are then pumped into the doped fiber optic cable that generates the laser beam.

The galvanometric drive system

There are several methods of directing the laser beam once it's created by the laser source. While flatbed laser machines use motorized belts to direct the laser beam with fixed mirrors, the galvanometric drive system uses high-speed, motor-driven mirrors to direct the beam through its lenses. Because there are no belts and the only moving parts are the mirrors, the laser beam is able to move at high speeds in an easily repeatable way. With galvanometric machines, you can achieve high-quality marking results with short cycle times while taking up less production space. 

Fiber laser F-theta scan lenses

The laser beam created with a galvanometric drive system moves in one or two dimensions. With a traditional lens, the focal point of the beam changes as the beam moves away from the optical axis. This change in focal point can result in defects in your projects. F-theta lenses correct this problem by focusing the laser beam onto an image plane without distortion. 

F-theta lenses are often used in galvanometric scanning systems that are comprised of two mirrors. One mirror controls beam deflection in one direction and the other controls beam direction in the perpendicular direction. The F-theta lens then focuses the laser precisely on the planar surface.

Fiber Lasers vs. CO2 Lasers

CO2 lasers and fiber lasers perform best on different materials of different thicknesses. The main difference between the two is how they create and transmit laser beams. CO2 lasers work by using CO2 gas to split light particle ions. These particles collide with each other, splitting even further. A pair of lenses then reflect and refocus the light down a "beam delivery system" to the cutting head. When the light reaches the cutting head, it's refocused and emitted to either mark or cut. The light that is emitted by a CO2 laser has a longer wavelength than the light emitted by a fiber laser.

CO2 lasers have been around longer than fiber lasers have been in use — for over 30 years — but fiber lasers are quickly catching up in frequency of use. One advantage fiber lasers have over CO2 lasers is their cost. Fiber lasers are more efficient and cost less to operate. They're also easier to maintain, making them an attractive option for small businesses and crafters. CO2 lasers perform better on thicker materials. Fiber lasers, on the other hand, have a clear advantage on thinner materials and perform much faster.

Is a fiber laser better than a CO2 laser? 

Fiber lasers perform better than CO2 lasers at certain tasks. They produce a more concentrated laser beam, so they're great for jobs that require precise, high-contrast marks. Fiber lasers are much faster than CO2 lasers and cause less damage to the surrounding material because they only affect the surface layer. They also take up less space. 

CO2 lasers, on the other hand, can be used on a wider variety of materials, including glass, plastic, leather, wood, and stone, among others. CO2 lasers perform better on thicker materials as well. However, you have to be careful when using CO2 lasers on highly reflective metals, since the laser could be reflected back into the machine, which could damage it.

Ultimately, the choice between a fiber laser and a CO2 laser will depend on several factors, including: 

• The type of material you're engraving
• The thickness of the material you're cutting
• The volume of marking you'll be doing

If you're primarily going to be working with metals, hard plastics, or stone, a fiber laser machine may be a better choice. If you're going to be working with wood or other soft or porous materials, a CO2 laser will be your best option. You may also want to choose a fiber laser marking machine if you plan on doing a lot of marking, if you need to be able to do it quickly, or if you want a low-maintenance laser engraver.

Which Materials Can a Fiber Laser Engrave or Mark?

Fiber lasers can engrave or mark a variety of different materials, but they don't work on all materials. If you want to engrave metal with complicated graphic patterns, serial numbers, or bar codes, fiber lasers are an excellent option. They're also a great choice for jewelry engraving and other hobby projects. Unlike with CO2 lasers, you don't need to use a bonding solution when you use a fiber laser marker on metal. Fiber lasers work best on materials that are hard and brittle, such as metal, stone, and hard plastics.

Materials you can engrave or mark with fiber lasers include: 

• Acrylic
• Hard plastics
• Brick
• Granite
• Marble
• Tile
• Aluminum
• Gold
• Silver
• Stainless Steel
• Brass
• Titanium
• Tungsten

Fiber lasers work well on PVC (polyvinyl chloride) materials. However, some PVC acrylics can create toxic fumes when they're lasered. PVC is a polymer that contains chloride. Heating PVC breaks it down, causing it to release hydrochloric acid, a toxic gas. If you're using a fiber laser on PVC, you'll need to make sure you're using a trustworthy fume extraction system capable of handling the toxic gas.

Another consideration when using PVC with a fiber optic laser is dechlorination, a decomposition process that occurs as PVC is heated. When the chlorine is released, it causes yellowing around the area that was marked with the fiber laser.

Can a fiber laser engrave wood?

Fiber laser marking machines cannot engrave wood. Fiber lasers have a shorter wavelength than other types of lasers, which allows the fiber laser to penetrate the wood. This causes heat to build up and will eventually cause the wood to catch fire. This is extremely dangerous, especially because wood can feed a fire.

Additionally, fiber laser engravers don't provide optimal results on wood. The high intensity of a fiber laser beam makes it hard to control its absorption into porous materials. Since the absorption rate can't be controlled, the marks a fiber laser produces on wood are unpredictable. Even if your wood doesn't catch fire, the engraving may be burned in some places and barely visible in others. You won't be able to achieve precise, repeatable results, which is the main reason most people are interested in a fiber laser in the first place.

Can a fiber laser cut glass?

Fiber lasers can't be used to cut glass, mainly because of the wavelength of the laser beam it produces. Fiber lasers work by causing a layer of the material they're marking to absorb the light and melt. Glass absorbs very little light on the visible spectrum, so it's not compatible with fiber laser markers.

How Much Does a Fiber Laser Marking Machine Cost? 

The prices of fiber laser marking machines vary greatly depending on the source. Many high-end systems cost tens of thousands of dollars. While it's possible to buy cheap fiber laser machines, they're often of poor quality and either won't perform well or won't last long. It's difficult to find a high-quality machine at an affordable price.

Although large manufacturers can justify spending a large amount of money on expensive machines, small businesses, crafters, and hobbyists usually can't afford to spend $30,000 or more on a fiber optic laser. OMTech noticed this gap in the market and designed machines meant to provide you with the best quality laser engravers at reasonable prices.

Where to buy a fiber laser marker machine

OMTech is a stand-alone brand that offers quality laser engraving machines at affordable prices. Before starting the brand, OMTech founders had over ten years of experience in the laser engraving industry. They now have laser machines for every need. Whether you're a hobbyist who needs a desktop engraver or a small business that needs a more powerful device, OMTech Laser has the best solution for you. 

OMTech builds laser engravers to function intuitively, so you don't need an engineering degree to use one. You can access advanced laser capabilities with the touch of a button. They understand that laser engravers are an investment, so they also offer financing options for customers. DIY crafters and small businesses can now take advantage of flexible payment terms to buy a quality laser engraver. 

They've built an online community of hobbyists, artisans, and businesses that share laser knowledge and solve problems together. They also provide top-notch customer support so you can get the most out of your laser machine. Reach out to OMTech today to see how they can help you start your laser journey.