INTERFEROMETER FOR MEASURING LINEAR DISPLACEMENTS OF OBJECTS Russian patent published in 2021 - IPC G01B9/02 G01B11/00 

FIELD: measuring devices.

SUBSTANCE: invention relates to instrumentation and namely to interferometric measurements of linear displacements of objects. The interferometer contains a two-frequency laser (1) of linearly polarized radiation and a diffractive phase modulator (3), an optical element (5), a half-wave phase plate (7) installed behind the optical element in the path of one of the beams, reflectors (8), (20) and beam splitters (9), (17), (18), (19), (21) for the formation of reference and working channels including polaroids and photodetectors, collimators. The collimators are structurally made of three positive lenses (2), (4), while the first positive lens is common for two collimators and is located between the laser (1) and the phase modulator (3), and the other positive lenses (4) are located behind the modulator in the path of each of the beams. The plane of rulings of the circular phase diffraction grating of the modulator is in the focus of the first common positive lens of the collimators (2).

EFFECT: invention increases the output useful signal of the interfering beams.

5 cl, 1 dwg