Vanadate laser - terminology and areas of application
The vanadate laser, chemically Nd:YVO4 is a solid-state laser that is usually diode-pumped. This laser source is similar to the Nd:YAG laser, but has a different host crystal (YVO instead of YAG). A neodymium-doped yttrium-vanadate crystal is used in the vanadate to generate the laser beam. As the laser emission takes place via the neodymium doping, the vanadate laser has a wavelength of 1064nm, the same as the YAG laser.
Advantages of the laser system
Data plate made of anodised aluminium with plain text and machine-readable codes
The vanadate pump is easier to pump, with the absorption band being significantly wider than that of the YAG laser. This has the advantage that the wavelength drift of the pump diodes such as through heating causes less fluctuations in the output power. The optical - optical efficiency is higher than that of the YAG laser, therefore the removal of waste heat is less critical or the output power (with the same crystal volume and same crystal geometry) is higher.
Vanadate lasers can be used to mark a wide range of different materials, generally the same materials that can be laser marked with a YAG laser. Laser marking of virtually all metals, plastics and partly organic materials is possible. The vanadate laser can deliver more pulses per second than the YAG laser. This can be advantageous for fast laser markings on plastic, as there is still pulse overlap.
A laser can generally only interact with a workpiece if it has sufficiently high absorption. Any power that is reflected or transmitted cannot be used for material processing.
As the laser emits in near infrared, as a rule of thumb it can be stated that any material that is transparent to the human eye cannot be processed with near infrared. Therefore, non-coloured glasses, Plexiglas, polystyrene and similar materials cannot be processed. This is possible with a CO2 laser.
Low running costs
The YVO4 laser requires no additional operating costs besides electricity. Thus, the laser system is considered very cost-effective in daily use and is increasingly replacing conventional marking systems, such as those that use ink and labels. With both the YAG and the vanadate laser, the pump diodes should be replaced after approximately 15,000 - 20,000 operating hours. This is a disadvantage compared to fiber lasers whose pump diodes are not subject to regular maintenance intervals.
Unlike inkjet printers, laser systems offer higher print quality, lower running costs thanks to no additional consumables being required and are extremely low maintenance. However, the investment is significantly higher.
If pre-printed cardboard is marked with the laser system, a well-contrasted marking with a short marking time is produced on the substrate.
How durable are the markings with the laser system?
Marking of a hydraulic hose used in harsh industrial environments
Laser markings generally have a very high durability, as the marking often takes place in the volume of the material rather than just on the surface. Unlike printed images, texts or barcodes, laser markings are resistant to abrasion and completely smudge-proof. They are even resistant to solvents, oil, weak alkalies and acids, as well as high temperatures. This is one of the reasons why laser marking systems have become increasingly relevant in recent years when it comes to the safety-relevant marking of components - for example, to prevent counterfeiting. In cars too, there are more and more components that have been laser marked. This includes dashboard switches, data plates, safety-relevant markings such as seat belt buckles and expensive components, including engine components like camshafts.
