DISPLACEMENT METER WITH VOLUME HOLOGRAM Russian patent published in 2001 - IPC

FIELD: optics, optical measurement of displacement. SUBSTANCE: invention can find use in high-precision contact-free interference-holographic measurement of displacement of objects. Displacement meter has point source of coherent optical radiation, optical system, beam splitter, reflector coupled optically and placed in sequence. Beam splitter is photographic plate with volume Fourier hologram containing strata in the form of collection of truncated hyperboloids placed one into another and having elliptical shape in plane of section of emulsion of hologram exposed according to law :0 <sin Q <d/h, where d <h; Q is angle included between hologram and reflector placed behind it during exposure and forming object light flux; h is distance along normal from reference point source to plane of hologram; d is distance between hologram and reflector along normal to hologram which is measured from reference point source. Photodetector is employed to register optical difference of path of object and reference light fluxes by measurement of parameters of information interferogram. Displacement is determined on basis of measurement and analysis of change of parameters of interferogram in plane of photodetector which are caused by displacement of object of measurements. EFFECT: enhanced threshold sensitivity of meter, simplified process of reading of information on displacement of object of measurement and expanded range of measured displacements. 3 dwg