A Bit of History

Simply  put, lasers work because a coherent Beam of light is created and focused in such a way that the energy is concentrated into one small area.   Consequently, the beam is powerful enough to affect the materials to which it is exposed.  The way the light is generated and the wavelength of the specific Laser Beam will determine what materials are affected and how they are affected.

For example, for our industry, the popular fully enclosed flatbed CO2 Laser engraving systems, use a combination of gasses to create the LASER beam which will vaporize woods, plastics, acrylics, paper, fabrics, etc. resulting in laser engraving and cutting applications. Then there are the YAG lasers that have been around for some time.

YAG lasers generate their light source through a combination of a glass crystal and electronics. The glass crystal is actually a rod composed of Ytrium Aluminum Garnet: or for short, “YAG”   A YAG laser works muck like a CO2 laser by vaporizing the material on which it is focused, leaving behind the desired "mark". In order to produce the mark, the generated beam of light needs to be absorbed by the material on which it is engraving. One of the differences between the two types of lasers (YAG and CO2) is the wavelength of the light that is generated which for practical purposes, defines the materials on which the laser can effectively mark.

The beam of light produced by a YAG laser is absorbed by highly thermal conductive, ferrous and some non ferrous materials. This includes most metals, plastics, ceramics and more.  Other materials, including wood, do not do very well with this particular wavelength.  

The first generation of YAG laser marking systems used flash lamps to generate the laser beam within the system.  These flash lamps are limited in life span, expensive to replace and also require technical expertise to operate, maintain, and repair.   Plus they generate a lot of heat, which needs to be removed, making them fairly inefficient to operate.  The next generation of YAG markers replaced the flash lamp with a diode pump system, which, for many applications works well, and eliminates the need for replacement of the expensive flash lamps when they fail. The diode pumped units are easier to maintain and operate, but the diode pumps have limited life spans and are expensive to replace.

Another alternative to the YAG laser is the Vanadate Nd YV04, which is similar, but uses a different element to create the crystal.  The applications for the Vanadate are similar to the YAG.

The intro of the Fiber laser

For the latest in laser technology, we now have the new state of the art fiber laser, which may end up replacing the YAG, as well as the Vanadate for many applications. The fiber lasers are created with a network of fiber optic cables and diodes.  And while the diodes do occasionally wear out, the manufactures claim that they will work maintenance free up to 100,000 hours. Fiber lasers are now being used for welding, etching, and cutting applications.  

Advantages of the Fiber laser marker

Fiber lasers used for laser marking and engraving applications, tend to use 110 VAC electrical current to run them.  Because they are so much more energy efficient, up to 25% efficient input to output of laser beam, compared to a traditional flash lamp YAG, ~1.5% efficient, they can be run in facilities that do not have 3 phase industrial electrical service.  (CO2 lasers, which most of us are familiar with, generally will run at ~ 30% efficient)  Also, because they run so much more efficiently than some older technologies, they do not need extra Chiller coolers to maintain operating temperatures.  Additionally many of the fiber lasers are built on sold state technology, are fully modular and do not have accessible internal Optics to service or align.  This translates into a system that is easier to operate and service, so hiring expensive technicians to repair the system is typically not needed.  Engraving fields are similar to YAG marking system fields, up to 12” square, with galvo based systems, but there are flat field engraving/ marking systems that will engrave on a 24” X 12” platform.  Clear concise text and/or graphics, dot matrix, UID, bar codes and more are created at high speeds (up to 350 characters per second). Open architecture software is also a plus making it easier to learn and operate .than some of the past YAG laser models.

Fiber lasers do generate the same wavelength as a YAG and Vanadate (1.064 nanometer) ant therefore are very versatile and efficient at marking on a range of materials including bare metals, coated metals, plastics, and more.

Pricing of Fiber laser marking systems does  seem to be competitive with the pricing of the more traditional YAG systems. The ones we are familiar with start at about $35,000 and go up from there, depending on design, manufacturer, and options.

Disadvantages

Because the wavelength of the laser beam is the same as the wavelength of the YAG the safety precautions are similar including the need for eye protection.  Additionally, there may also be OSHA, state and local regulations that apply as to the general overall operating environment.. The fiber laser markers also have some limitations and are unable to mark some materials that YAG’s can, due to the peak pulse Power frequency required. This includes achieving dark marks on white ceramic and/or effectively high contrast marking of some acrylics. 

Options

The fiber laser markers that we have seen come with a 10 or 20 watt laser, which for practical purposes, translates into Speed and capability. Additionally, there are fully enclosed flat bed flying optic models (similar in design to the common CO2 engravers), galvo headed systems, OEM models, stand alone models or fully enclosed work station configurations available.  For some applications, additional automation equipment can be added.

Summary

The fiber laser is the latest laser technology available. These household current powered, air cooled, minimal maintenance laser markers provide a variety of opportunities for all engravers involved in the direct parts marking and product identification industries, as well as what is currently being done in traditional ARA affiliated shops.