Since the laser was invented, galvanometer (galvo) scanners have been used for scanning the beam.
Galvos are ideal for high power / low speed material processing applications. Every year laser power goes up. Higher power allows faster processing which means running the galvos faster. Galvo manufacturers have continuously improved galvos to go faster. Galvo motors gained more torque. Lighter and stiffer mirrors became available. Galvo scanning is now a very mature technology which means we can expect only small incremental opportunities to increase galvo scan speed. Meanwhile, laser power is going up at a strong rate every year.
In high fluence applications, like welding steel, galvo scanners are plenty fast enough. In low fluence situations, such as thin film ablation with a high pixel density, galvos are not fast enough. It is unproductive to contact every galvo manufacture asking for a galvo to go twice as fast than the technology allows. (Every photonics trade show I have exhibited at, there were galvo users going booth to booth seeking a galvo scanner that was much faster than the fastest in the world. They all went home disappointed.)
Polygon scanners should be considered when galvos are not fast enough. While polygon scanning has been providing fast and highly accurate laser scanning for over 40 years, polygon technology is completely foreign to the vast majority of people designing and using galvo systems for material processing.
Polygon scanners have dominated high speed / low power applications such as laser inspection and laser printing. It is a raster scan technology. It is most suitable where there is a high pixel density in the work area. Polygon scanning works very different from galvo scanning so it can be very confusing to make the change. Precision Laser Scanning has a wealth of expertise in polygon scanning and can assist those seeking how to implement high speed polygon scanning technology.