Steering Light: What Is The Difference Between 2-Axis Galvo Scanners And Single Mirror 2-Axis Scanners

When it comes to steering light precisely in two dimensions, optical system designers have several established technologies at their disposal. Examples include galvanometer mirror scanners (galvo scanners) piezoelectric fast steering mirrors, voice coil-driven steering mirrors, kinematic mirror mounts, and gimbal mounts. Each one of these were designed for specific applications and this article will describe a few of their strengths and limitations.

2-Axis Galvo Scanners – 2 Individual Mirrors

These optical scanners consist of two independent, perpendicular rotating planar mirrors, arranged in a way that laser light bouncing off the first mirror (axis 1) will hit the second mirror (axis 2) and from there on, the target.

Galvo scanners are often used in laser material processing, and their large production numbers allow for relatively low cost. Due to the lightweight mirrors, highly dynamic motion in closed-loop operation is feasible, with step response times in the sub-millisecond range. Another advantage of galvo scanners is their large scanning field, typically around 20 degrees for both axes.