The main difference in most laser machines on the market is the source of the laser they use. Here, we concentrate on CO₂ lasers, fiber lasers and vanadate lasers. Each individual laser type is suited for different needs and applications, and has its own advantages and disadvantages.
CO2 lasers are gas lasers based on a carbon dioxide gas mixture, which is electrically stimulated. With a wavelength of 10.6 micrometres, they're useful for working on non-metallic materials and on most plastics. CO2 lasers have a relatively high efficiency rate and feature a great beam quality, so it's little surprise that they're the most widely used laser type.
Fiber lasers are a member of the solid state laser group. They generate a beam using the 'seed laser' and amplify it in specially designed glass fibers which are supplied with energy via pump diodes. With a wavelength of 1.064 micrometres, fiber lasers produce an extremely small focal diameter, making their intensity up to 100 times greater than the intensity of CO₂ lasers with a similar emitted average power.
Fiber lasers are highly suited for metal marking by way of annealing, for metal engraving and for high-contrast plastic markings. They're usually maintenance-free, and promise a long service life of at least 25,000 laser hours.
A special type of fiber laser is the MOPA laser, where pulse durations are adjustable. This makes the MOPA laser one of the most flexible lasers which can be used for many applications.
Suited for the following materials: Metals, coated metals, plastics
Just like fiber lasers, crystal lasers are members of the solid-state laser group. Nowadays, lasers for marking applications are pumped by diodes (or flash lamps in the past). The most common laser types in this category are nd:YAG (neodymium-doped yttrium aluminium garnet) and Nd:YVO (neodymium-doped yttrium ortho-vanadate), named after the neodymium doping element and carrier crystal.
With a 1.064 micrometres wavelength, crystal lasers have the same wavelength as fiber lasers and are also therefore suited for marking metals and plastics.
Unlike fiber lasers, though, these laser types include relatively expensive pump diodes, which are wearing parts. This means that they must be replaced after approximately 8,000-15,000 laser hours. The crystal itself also offers a shorter service life than a fiber laser.
Suited for the following materials: Metals, coated metals, plastics, to some extent also for ceramic.