DEVICE MEASURING TRANSLATIONS Russian patent published in 1997 - IPC

FIELD: measurement technology, measurement of linear translations. SUBSTANCE: radiations polarized by left and right circles passing through λ/4 through are converted to radiations with crossed linear polarizations. Polaroid which polarizer axis is oriented at angle of 45 deg to axes of quarter-wavelength plate produces radiation of only one polarization. Linearly polarized radiation goes to reflector attached to object, is reflected from it and is converted again by l/4 plate to radiation of circular polarization but of opposite direction. Radiation of one circular mode passed through measurement arm sums up with radiation of another circular mode generated in laser, and phase locks it with itself. Translation of reflector causes turn of azimuth of polarization of summary radiation of laser and polaroids convert rotation of polarization plane to changes of radiation intensity at photodetectors. Since polarizer axes of polaroids are oriented at angle 45 deg relative to one another then signals phase-shifted through 90 deg go to photodetectors. This standard technique provides for registration of not only value but direction of translation of reflector. Device includes traditional processing unit which key elements are former of pulse sequence and reversible counter. Azimuth of polarization plane of summary radiation of laser formed as result of phase coupling of two types of oscillations through measurement arm is used as information source. EFFECT: enhanced functional efficiency and reliability of device. 1 dwg