Carried out in jewellery and fine art applications, laser engraving is principally an industrial process which uses a laser to make finely positioned marks on an object. Often a professional service that is offered by a laser cutting company, the process does not require tool bits to make physical contact with the surface that is to be engraved. This offers a benefit over traditional engraving technology which requires items like bit heads to be replaced regularly.
Laser engraving is conducted by a machine which contains either a solid-state or a gas laser. Both produce a high discharge of energy in the form of light—a laser beam—which can then be utilised for either melting or evaporating a material. Laser engraving machines use a variety of positioning systems, also known as laser plotters or galvanometer scanners, in order to direct the beam to precisely where it is needed. These movement systems can be fully automated according to the design of the engraving by software. Because the laser beam is manipulated using a system that is free from any form of wear, the machine will never become blunt. This means that many, many engravings can be made identically without having to reset or recalibrate the system, thereby affording considerable savings through efficiency.
Among the commonest forms of laser engraving machine is the so-called X-Y type. With this approach, the item to be engraved is stationary, while the laser's positioning system moves the beam around according to an imaginary grid, over the horizontal X axis and the corresponding Y axis. This allows the beam to engrave any desired design in the form of vectors. Other sorts of systems have both the workpiece and the laser in a fixed position stationary while galvo mirrors are used to manipulate the beam to where it is needed.
Different designs can be laser engraved by programming the machine to traverse at particular speeds as well as paths. The longer that a beam rests in one place, the deeper the engraving will be. Conversely, a faster moving beam will allow for a shallower engraving to be produced. The speed and path of laser beam in an engraving machine is known as its trace. A beam's trace is carefully regulated so that the engraved depth of the material matches the design exactly. In most applications, this means ensuring that the depth of engraving is uniform, but this is not always the case for some of the more creative uses of laser engraving. Indeed, altering the both the intensity and the spread of a laser beam provides even more flexibility with all sorts of engraving effects being possible today.