How to make the right decision when choosing the best laser for a marking application? An understanding of the laser characteristics and the material properties is essential to making an optimal choice. In laser marking processes, the type of material, quality of mark required, and speed will all play a role in the optimum choice of a laser.
There are several technology options when choosing a pulsed laser for marking:
- Nd: YAG
The Nd: YAG laser was introduced more than 25 years ago and is the workhorse of the industry. One advantage of Nd: YAG lasers are their high beam quality, which leads to a smaller spot size of the laser: the small spot size, along with short pulses, produces high peak power that can be beneficial in deep engraving with crisp, clear marks and small characters.
- Nd: YVO4 (vanadate)
The vanadate laser can emit at three different wavelengths: 1064, 532 (green), and 355 (blue) nm. Such lasers deliver high beam quality with pulse-to-pulse stability too. It makes them well suited for ablation marking and heat-affected zone (HAZ) applications.
Fiber lasers do not have the same beam quality as Nd: YAG or vanadate lasers, which limits the amount of peak power available. The fiber laser can anneal stainless steel due to its long pulse width and larger spot size, putting more heat in the part to draw the carbon to the surface. Not so many fiber laser manufacturers offer the laser source to a third party for integration into a marking system.
One major benefit of ytterbium-doped fiber lasers is that the near-infrared 1070 nm wavelength emitted is dose enough to the 1064 nm wavelength of neodymium-doped Yttrium aluminum garnet (Nd: YAG) lasers as to make no difference during the actual process of laser marking. This made for a relatively easy replacement of continuous wave Nd: YAG lasers by fiber lasers for most marking applications.
It is also important to understand how the material to be marked absorbs laser light at the wavelength of the laser chosen. Ferrous and non-ferrous materials have excellent absorption at 1064 nm, while precious metals do so at 355 and 532 nm. Plastics also absorb the higher wavelength laser output. In terms of operating costs and consumables, these three laser systems are almost identical, so an end user can choose the optimum laser technology without having to make cost tradeoffs.
The most common terms used in laser marking include engraving, annealing, ablation, and color change of plastics.
All three laser technologies will have a place in industrial manufacturing for years to come. The technology will continue to evolve in order to meet the changing demands of the manufacturing environment.
Optromix Inc., headquartered in Cambridge, MA, USA, is a manufacturer of laser technologies, optical fiber sensors, and optical monitoring systems. We develop and manufacture a broad variety of fiber lasers, СО₂ lasers, Ti: Sapphire lasers, dye lasers, and excimer lasers. We offer simple erbium laser and ytterbium laser products, as well as sophisticated laser systems with unique characteristics, based on the client’s inquiry.
We manufacture lasers using our own technologies based on the advanced research work and patents of international R&D team. Laser processes are of high quality, high precision, easily-automated manufacturing solutions that provide repeatability and flexibility.
If you are interested in Optromix fiber laser systems, please contact us at email@example.com more