APPARATUS FOR NANOMETER ACCURACY LINEAR DISPLACEMENTS IN WIDE RANGE OF POSSIBLE DISPLACEMENTS Russian patent published in 2013 - IPC G01B11/00 G01B11/14 

FIELD: physics.

SUBSTANCE: apparatus has a fixed part, a movable part on which an object is mounted, a monochromatic radiation source, a single-mode light guide, a point source superimposed with the front focus of an optical system, two parallel transparent plates placed perpendicular to the optical axis. The first plate is mounted on the fixed part and on its periphery on the side facing the second plate at an angle of about 120° to each other, there are three areas with surfaces inclined towards the plane of the plate with level difference from the centre of the plate to its edge having a value equal to at least half the wavelength of the monochromatic radiation. The second plate is mounted on the object and three actuators are mounted on its periphery at an angle of about 120°. Behind the second plate there are three linear matrix photodetectors interfaced with areas of the inclined surface, wherein outputs of said photodetectors are connected to inputs of a computer. Outputs of the computer are connected to the drive of the movable part and the three actuators. Surfaces of the areas of the inclined surfaces and the second plate facing each other are made with a highly reflective coating.

EFFECT: moving an object with nanometer accuracy in a wide range of distances.

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