METHOD OF CONTROLLING PHASE SHIFT IN INTERFERENCE SYSTEMS Russian patent published in 2018 - IPC G02F1/11 G01B9/02 

FIELD: measuring equipment.

SUBSTANCE: in the method of controlling the phase shift in interference systems, including the formation of coherent monochromatic radiation by the laser source, its separation into the reference and object light beams by a collimating system, directing them on measurement object and supporting surface to form a phase shift in them intended for the interpretation of interference pattern at their reflection on the photodetector, the phase shift Δϕ of the reference and object light beams is formed by their Bragg diffraction on the similar by number and sign orders by passing on the section between collimating system and the support surface and the measurement object, respectively, through identical acousto-optic modulators, on which the reference vibrations U₁ and U₂ are fed from the common generator so that U₁=U₀ cos[2π f×t+Δϕ] and U₂=U₀ cos[2π f×t], where U₀ is amplitude of reference oscillations; f is frequency of reference oscillations of acousto-optic modulators; t is the time of reference oscillations, and it is possible to supply the reference oscillations U₁ on the acousto-optic modulator through which the object light beam passes, and the reference oscillations U₂ - on the acousto-optic modulator through which the reference light beam passes, or vice versa.

EFFECT: increased reliability through improved accuracy and noise immunity.

3 cl, 3 dwg