How does a Laser Cutter Work?

Desktop Laser Cutters & Engravers have become a staple in the home and the workshop, but how do these machines really work? Laser cutting is a high-powered form of subtractive manufacturing that uses a strong and hyper-focused beam of light to cut or engrave materials. These high-powered beams of light (lasers) can be generated in a variety of ways. The lasers used in laser cutters cut and engrave materials by burning, melting, and vaporizing the material it touches.

Depending on the type of laser used, the laser is directed at the material through a series of mirrors or shown directly on the material from the laser. The laser cutter creates patterns by following detailed instructions given to it in the form of computer numerical control (CNC) or G-code. These instructions are written by computer software, such as Beam Studio or LightBurn, that converts a traditional 2-dimensional image into a file that the laser cutter can understand.

Laser cutting can create incredibly detailed and precise objects out of a wide variety of materials such as wood, acrylic, metal, glass, leather, and more!

Types of Laser Cutters

While all laser cutters create detailed and precise patterns by directing high-powered lasers onto materials to cut, etch, and engrave, there are a variety of different kinds of laser cutters. Laser cutters vary from each other in 2 main ways.

1. Laser type and path
2. Laser power

Lasers can be created in different ways, and here we will go over the most common types of lasers in consumer grade laser cutters.

CO2 Laser Cutters & Engravers

CO2 laser cutters use CO2 lasers, or carbon dioxide lasers, are one of the most common laser types used in consumer-grade and desktop laser cutters. This is because CO2 laser engraving machines are incredibly powerful and one of the most cost-effective high-powered lasers available. They also create incredibly smooth cuts and engravings quickly.

A CO2 laser is created by pumping electricity through a glass tube filled with a mixture of CO2 and other gasses. The electricity excites the CO2 particles enough to start emitting light. The laser is then created by mirrors surrounding the glass tube reflecting the light back and forth until it is powerful enough to pass through a partially reflective mirror at the end of the tube. The laser is then directed at the material you want to cut or engrave through a series of mirrors.

Diode Laser Cutters & Engravers

Diode lasers are another common type of laser used in desktop laser cutting & engraving machines. The main advantages of diode lasers are that they are affordable and compact. Diode lasers are much more common in our daily lives than other types of lasers and used in CD & DVD players, laser printers, barcode scanners, and more.

Laser beams from diode lasers are created in a similar way to the light produced by LEDs (Light-Emitting Diodes). The laser is created by forcing electrical current through a semi-conductor creating a highly focused and powerful beam of light.

While diode lasers are typically less powerful, they do have one major advantage over CO2 lasers. Due to the wavelength of light produced, diode lasers can engrave and cut reflective materials (such as metal) at much lower power levels than CO2 lasers.

Fiber Laser Cutters & Engravers

Fiber lasers are the last of our most common lasers, and they are widely used in industrial applications for cutting, engraving, cleaning, welding, and much more. The main advantages to hobby-level fiber lasers are their ability to engrave metal very precisely and quickly.

Fiber lasers use fiber optic cables to guide light, making the resultant beam very small and precise. Fiber lasers are your best choice for engraving metals because of their shorter light wavelength. While fiber lasers can cut metal, that capability is usually only found in industrial-level machines, and most consumer-grade fiber lasers can only engrave materials.

Most consumer-grade fiber lasers come in the form of a galvo-head fiber laser. Galvo-head fiber lasers work by moving mirrors inside the laser head to point the laser beam rather than moving the laser head around on a gantry. This limits their work area, but also makes them super fast. Fiber lasers typically have lower maintenance costs, but the startup costs are typically higher than both CO2 and diode lasers.

Laser Power

The other major way that lasers differ from each other is the power level of the laser. Laser power is measured in output wattage. A 30W laser generates 30 joules of energy per second. But what does that mean for you? In it’s simplest terms, a more powerful laser can cut thicker materials faster.

The table below displays common materials used in laser cutters and the thicknesses that a 30W, 40W, and 50W CO2 laser can cut through.

While diode lasers up to 30W are rarely used in consumer-grade desktop laser cutters, the different wavelengths of light produced can cut through materials that higher powered CO2 lasers cannot. The table below shows the thickness of metal a 10W diode laser can cut through.

While this is not an exhaustive list of laser types; hopefully, you now have a stronger sense of how laser cutters & engravers work. With this newfound knowledge, you can now dive into the world of endless opportunities that is cutting and engraving with lasers.