Interferometer With Mercury Bearings
Original Publication Date: 1989-Feb-01
Included in the Prior Art Database: 2005-Jan-27
A balance beam provides frictionless movement of an interferometer mirror, as described in the reference noted below. The arrangement only works in a vertical orientation and is not constrained in any other axis; i.e., it is essentially a pendulum in a magnetic field, counterbalanced by a weight. Any movement along the perferred axis can cause the mirror assembly to swing. The implementation described here is a piston-like slide that permits movement in only the preferred direction, controlled by a precision linear actuator. (Image Omitted) The piston-like slide is constrained in a cylinder by a pair of mercury beads around the periphery of the slide. The movable mirror is affixed to the bottom of the slide. The basic principle of operation is predicated on the fact that mercury will not wet certain materials, e.g.