MACRO MOTIONS WITH MACRO FLEXURES WITH EMPHASIS ON VACUUM COMPATIBILITY

摘要

The drawback to attempting the strictest auto-focus requirements with a wedge stage alone lies in the kinematics of reacting wedge forces without perturbations in the X-Y plane, and the flexibility of the bearing that takes this reaction. Add to that the general pain of friction and stiction of linear rolling elements and seals that complicate sub-micron moves, let alone moves in the tens of nanometers. Air bearing implementations can cope with the latter, but at great cost. The former can be dealt with by geometry, using a balanced, differential wedge like our KAOS XZ style stage; though there are limitations to how low manufacturing tolerances of structure and bearings will allow the roll, pitch and yaw to go. An attainable lower limit for higher production stages would be roughly 8-10 arc-sec. The latter issues of stiction and friction will still make themselves known.