Laser Sensing and New Stator Designs for a Linear Slider

This paper introduces the use of laser beams for guiding a linear slider along the track with magnetic levitation. The paper will focus on the optical and magnetic design. control. and possible applications. Three parallel laser beams are positioned along the stator to define a plane along which the slider should be guided. The beams are reflected from the slider by three comer cubes. whose lateral displacements are then detected by three four-segment photodiodes situated on the stator side. The configuration allows the slider to be free of electrical components and possible source of contaminant. Introduction of digital control allows increased flexibility. For example. by feedback of the position of the slider along the track, it becomes possible to guide the slider along a designated plane or a curved surface. The system is applicable to sample transport in ultrahigh vacuum and clean rooms.