One of the main components of a galvo head is the dual mirrors. These mirrors, which are extremely small, can move at a fast rate. In fact, the mirrors can move so fast they appear to jiggle, and it is this jiggling motion that helps position the laser beam.
An equally fundamental part of the galvo head is the controlling component, which is made up of computer-driven servo drivers that are used to guide the movement and position of the mirrors. When the position and angle of these mirrors change, the laser beam moves to different locations on the laser bed.
A laser source is required for this technology to function. The laser source is attached to the galvo head and can include a single type of laser beam such as CO2, nd:YAG, or fiber.
—Richard Korbyl, Columbia Awards