Abstract: A polarizing optical arrangement wherein a linearly polarized signal beam cluster is generated. The signal beam cluster is created from interfering partial beam clusters and is linearly polarized. The azimuth of oscillation of the linearly polarized signal beam cluster is dependent on the mutual phase relationship of the aforementioned partial beam clusters. A splitter grating splits the linearly polarized signal beam cluster into partial beam clusters that are analyzed by analyzers, detected by photoelectric transducers and phase-shifted electrically from one another.

Abstract: A position measuring apparatus includes an optical instrument placed in a first plane, a first diffraction grid placed in a second plane, parallel to the first plane, a retro-reflecting element, a second diffraction grid, and an optical element, preferably placed in the first plane. The optical instrument splits a beam of light into at least two divergent partial beams which are diffracted by the first diffraction grid into parallel partial beams. The parallel partial beams are conducted through the retro-reflecting element and then impinge onto the second diffraction grid. The second diffraction grid diffracts the partial beams and causes them to interfere with each other at the optical element. A detection device measures a change (.DELTA.OPD) of path difference of the partial beams which is directly proportional to the change in distance between the first and second planes. This change (.DELTA.

Abstract: A position measuring apparatus for measuring the position of a first object relatively movable with respect to a second object. The position measuring apparatus includes a first deflection element, a light source positioned to scan the first deflection element with a light beam, a second deflection element, and a reflection element. The second deflection element and the reflection element are adapted with respect to each other and with respect to the first deflection element so that partial beam bundles deflected from the first deflection element are deflected by the second deflection element and emerge converging from the second deflection element into the reflection element, are reflected by the reflection element, and emerge diverging from the reflection element, impinge again on a deflection element, are deflected again and are brought into interference.