Phase-measuring interferometer

摘要: A heterodyne phase-determining interferometer comprising a Smartt point diffraction (PDI) 10 in which the pinhole plate 22 is replaced by half-wave, partially transmitting 22' with 20 therein. The output beams 26 and 24 from are propagated through frequency shifter 12 includes quarter-wave 28 whose axis at 45° to polarization axes of two coming PDI 10, half-wave 30 rotating an angular ω, linear polarizer orients vectors same direction along propagation axis. moving interference pattern consisting alternate light dark lines. This projected upon phase-measuring means 14 array photodetectors 34, 36 connected plurality phase-to-voltage converters 38. There one reference photodetector rest being test photodetectors. 34 all 38, but each different converter 38 phase difference between viewed its associated 34.