Air and magnetic bearings for a laser beam deflection unit

Laser interferometry is an established technology for accurate distance measurements. For flexible measurements in 3D, the laser beam has to be directed at a possible moving object. This goal can be achieved with a deflection unit, consisting of one or two mirrors. To maintain accuracy and bandwidth of the measurement device, this mirror has to be positioned accurately and fast. The paper describes two deflection units, one base on an air bearing and one on a magnetic bearing, as a possible design. Their construction, mathematical models and simulations are included