PHOTOELECTRIC INTERFEROMETER FOR MEASURING DISPLACEMENT Russian patent published in 1994 - IPC

FIELD: measurement technology. SUBSTANCE: light beam, which passes through beam splitter 5 of modulator 5, enters prism reflector 8, attached to object 9. After that the beam is focused by optical element and, being reflected from prism reflector 8 with preset focus length, enters beam splitter 5. When beam splitter is periodically moved, variable component of photocurrent signal is present in signal of photodetector 10. Phase of photocurrent signal is connected with optical phase difference between interfering beams, which is caused by movement of the object. EFFECT: improved precision of measurements; reduced phase errors of measurements. 1 dwg