TWO-FREQUENCY INTERFEROMETRIC SYSTEM FOR MEASUREMENT OF LINEAR MOVEMENTS Russian patent published in 1997 - IPC

FIELD: laser measurement technology. SUBSTANCE: two-frequency interferometric system incorporates laser sources, corner reflector coupled to object, two optical mixers, two photodetectors, electron unit for frequency-phase automatic adjustment which first and second inputs are linked to outputs of second photodetector and generator and which output is connected to piezoelement of second laser source and reversible counter which two inputs are coupled to outputs of first and second photodetectors. System is provided with second corner reflector, third optical mixer, third photodetector, additional piezoelement, high-voltage amplifier and phase detector which two inputs are connected to outputs of second and third photodetectors and which output is coupled to input of high-voltage amplifier which output is connected to additional piezoelement coupled to first laser source. First corner reflector and optical mixer optically couple first outputs of laser sources to first photodetector and form measuring optical arm of interferometer. Second optical mixer optically couples second outputs of laser sources with second photodetector and forms reference optical channel of frequency-phase referencing. Third optical mixer and second corner reflector couple second outputs of laser sources to third photodetector and form compensating optical arm of interferometer. EFFECT: generation of direct signal of movement with simultaneous simplification of registration system, increase of its reliability and reduced cost. 2 dwg