Laser Engraving Demystified: A Product and Technical Guide

2025-04-09 | By Jonathan Webb

Lasers, they appear everywhere, but do you truly know how they work and what they are used for? Two unique applications of lasers are in material cutting and engraving. Lasers have been used in industry for a long time, but only in recent years have they entered consumer-grade manufacturing devices. Laser engraving has recently become a very popular activity in the maker community. Let’s review the different laser technologies that exist, primarily focusing on the common types that might be seen in a consumer laser engraver. When looking at laser engravers two primary differences exist. These differences are the type of laser and the machine’s motion system.

Laser Module:

The laser module in one of these systems is a device that uses Light Amplification through Stimulated Emission of Radiation (LASER) to produce an immensely coherent and high-power beam of monochromatic light. Because this beam is monochromatic, all the photons are the same frequency. Because this beam is coherent, all the photons of light travel together in a straight line, causing the beam to spread a little over long distances. Both these characteristics and the high concentration of photons make this laser beam immensely powerful. Laser technology has gotten to the point where strong lasers can easily cut through inches of steel!

There are three main varieties of lasers commonly used in laser engraving; they are CO2, diode, and fiber lasers. CO2 lasers use a blend of numerous excited gases to produce a laser beam. CO2 excitation is the last step in the gas excitation process; hence where these lasers get their name. Diode lasers use semiconductor diodes to produce laser beams. Fiber lasers are one of the more advanced laser types. Fiber lasers use special fiber optic cables to collect and transmit light. The optic cable is created in such a way that it absorbs light photons and re-emits them at a specific frequency. The optic cable also narrows to channel the light into a very precise and concentrated beam. These lasers often use a source to produce mass amounts of photons that are collected, concentrated, and channeled by the fiber optic cable. Ultra-violet (UV) lasers are a more recently emerging subcategory of fiber lasers. These lasers are similar to fiber lasers but have a much higher frequency and often low wattage.

During my research, I found great visual demonstrations of how CO2 and Fiber lasers work. If these laser technologies have piqued your interest, I would recommend watching them so you can visualize the processes and learn more in-depth about how they work.

How Fiber Lasers Work

How CO2 Lasers Work

If you have a basic understanding of semiconductors, I highly recommend watching this video on diode lasers.

How Diode [Semiconductor] Lasers Work

Motion System:

The motion system of most laser engravers is a servo gantry system (also called linear gantry system or xy gantry system). This system uses two servo motors to control the x and y axis of the machine. The system can move the laser to any position by making each servo respectively move the laser vertically and horizontally. The other common motion system is a galvo-scanner aka “galvo”. This setup uses two mirrors that rotate and reflect a laser beam in the same xy coordinate plane. One mirror rotates moving the laser beam horizontally across the surface, and the other mirror moves it vertically. A galvo moves a laser extremely quickly with much higher accuracy but is limited to a very small working area. Servo gantry systems allow a much bigger work area but at the expense of accuracy and movement speed. Galvo-scanners are exclusively used with fiber lasers, UV lasers, and a few CO2 lasers. Servo gantry systems are primarily used with CO2 and diode lasers. Industrial metal laser cutters use large servo gantry systems with a very strong fiber laser.

Various Considerations:

Industrial laser devices are in a class of their own, making them hard to compare. Different consumer-grade laser engravers do have significant differences that are worth noting. The differences between many products include price, laser lifespan, beam wavelength, beam strength, accuracy, and focus. These differences affect the application and effectiveness of the laser device.

As far as price goes, for comparable wattages, diode lasers are the lowest cost, followed by CO2, and then fiber. Fiber lasers are often very expensive, many times the price of diode lasers. UV lasers are the most expensive per watt of laser power.

In regard to lifespan, fiber lasers have the longest lifespan of up to ~100,000 hours followed by diode with ~5,000-50,000 hour lifespans and CO2 with ~8,000-20,000 hour lifespans. UV lasers have a lifespan slightly higher than CO2 lasers but less than diode lasers. Continuous high-power usage is the factor that affects these lifespans the most.

Different laser types have different beam wavelengths. These beam wavelengths cause the laser beam to be absorbed better by different materials. Fiber and CO2 lasers are often in the infrared range, light below the frequency humans can see. A common Fiber laser wavelength is 1064 nm, and a common CO2 is 10,600 nm. Both are invisible to the human eye, making them especially dangerous to work with. “Diode” lasers are often similar wavelengths to blue light ~495 nm. Most diode lasers are visible, making them somewhat safer and easier to work with. Ultra-violet lasers, although less common, are also worth listing. With a wavelength of 355 nm, they are also invisible to the human eye.

Accuracy and focus are other important characteristics. Typically, CO2 and diode lasers are less accurate, while fiber lasers are very accurate. UV lasers are regarded as the most accurate.

Material Compatibility:

Different lasers are best used on specific materials. Diode lasers have the most limited applications and are primarily used on organic materials (wood, leather, paper, cardboard, etc.), opaque acrylics, and certain ceramics. They struggle with glass and metals.

CO2 lasers have similar limitations to diode lasers, but they can work with some transparent materials that diode lasers simply pass through. They also are minorly effective at lightly engraving metal. Additionally, they can adequately engrave glass treated with carbon spray or paper. They cut far thicker materials compared to diode lasers but still can’t effectively cut metals.

Fiber lasers are specialized for working with metals. They can deeply engrave and cut metals like aluminum, brass, gold, silver, and even some steel. They can even deeply engrave ceramics. They are excellent for engraving and cutting small objects.

UV lasers are the best for marking glass and specific plastics but have limited applications.

Laser Engraving Demystified: A Product and Technical Guide

I am not affiliated with this company, but here is a great video comparing UV, CO2, and Fiber lasers engraving various materials. It also demonstrates the speed (and awesomeness) of a galvo-scanner.

To conclude, I just want to express my personal satisfaction with laser engraving as a hobby. During my sophomore year as a Mechanical Engineering student, I bought a 40w diode laser engraver, and I have not been disappointed! Although many of the other lasers discussed in this blog are far more advanced and have many benefits, nothing beats the cost-effectiveness and versatility of a simple diode laser engraver. Caution must be taken because it has an open frame, which can present some safety risks, but with caution and proper PPE, this is the laser engraver that helped me get into laser engraving and complete many fun engineering projects! For anyone who loves 3d printing, CNC, woodwork, or digital art, I highly recommend you take a crack at laser engraving. You will not regret it!