How Laser Engraving Works

The System

Laser engraving is the application of marks or designs to an object through the use of a powerful laser. Although simple in concept, the process of laser engraving is quite complex. A laser engraving system usually involves two main components, the laser and the controller, in addition to the surface to be engraved. The laser is a light that produces a specific "stimulated" emission, producing a visible beam that, when powerful enough, can chip away or even vaporize the surface of certain materials. Because of the precise nature of laser engraving, it is a craft too unstable to be performed by even the most steady hand. This is where the controller enters the picture. The controller comes in a number of forms but is generally a computer system that orchestrates the precise and steady movements required for laser engraving. Either the laser will move, "drawing" vectors onto the surface, or the controller will move the surface in relation to the laser. There are also laser systems designed for unique situations, such as in engraving 3-D objects.

The Process

There are many considerations that must go into every step of making a laser engraving. Although laser engraving has the advantage of incredible precision, this precision necessitates a similar level of preparation. Unlike other forms of engraving that can be performed by hand, the design to be engraved cannot be improvised. The programmed design is the exact pattern that will be followed by the controller in relation to the laser. Because a laser can provide a consistent engraved depth, the system will never cross over the same point twice. This perfection in every aspect of design requires additional coordination of the laser's intensity and width. The focal point, where laser and surface meet, can become very hot, necessitating focused and reliable cooling systems. Additional factors, such as varied surface height or curved surfaces, can necessitate complex automatic focusing systems. All of these factors combine to make the process of laser engraving a powerful but labyrinthine combination of careful design, programming and overcoming physical obstacles.

Materials

Although laser engraving can produce impressive results, its application is slightly limited by the "laserable" materials. Wood, plastic, stone, metal and glass can all be subjected to laser engraving, but diverse hardware needs and material limitations may affect each surface in a different way. For example, although wood can withstand treatment with lasers, too much intensity can vaporize or burn the material, necessitating careful technique and exceptional cooling. Metals prove even more of a problem. Although easily subjected to traditional engraving, it is only with the advent of shorter wavelength lasers, such as newer 1,064 nm neodymium crystal lasers, that metal has become regularly engraved with lasers. Because of the incredible planning and specificity needed to suit different types of engraving on different types of material, laser engraving has long been predominantly a commercial practice, suitable to those businesses that can afford the equipment. However, thanks to increased flexibility and compact controllers, laser engraving can be used a greater and greater set of situations, such as the design of jewelry or even fine art.