Grating interferometer with diffraction screens in series - makes multiple use of resulting diffraction orders as multiple or non-polarised heterodyne interferometer or interference spectrometer
DE4028050A1
Grating interferometer measuring straightness of machine guides - detects offset of directional beam w.r.t. grating and phase shift indicating deviation from linearity
DE4018664A1
Grid refractometer measuring refractive index and/or stabilising - has stable air gap for use as beam splitter for wavelengths of EM radiation in medium
DE3918812A1
Distance-measuring heterodyne interferometer
DE3918811A1
Heterodyne interferometer
DE3911472A1
Method for the refractometric measurement and stabilisation of wavelength or frequency
DE3911471A1
Heterodyne method for refractometric measurement and stabilisation of wavelength
