Interferometer phase shifting device

Abstract

An interferometer phase shifting device includes a gas-tight container, a first optical fiber coupler and a second optical fiber coupler, a first optical fiber transmission line and a second optical fiber transmission line connected to the optical fiber couplers, and a gas pressure control module or a temperature control module, wherein the first optical fiber coupler and the second optical fibercoupler are aligned with each other. The interferometer phase shifting device provided by the invention utilizes a method of changing the refractive index of gas by changing the pressure or temperature of gas in a container to generate a continuous phase shift outside an optical path of a measurement imaging system, eliminates a system error generated by a traditional phase shift, and has the advantages of low cost, simple structure and easy assembly operation.

Description

technical field [0001] The invention relates to the field of interferometric measurement, in particular to a simple phase shift device that generates phase shift outside the optical path of the measurement imaging system. Background technique [0002] In a variety of experiments and systems based on interferometric optics, it is desirable to control the phase of the beam, including point diffraction interferometer, transverse shear interferometer, phase profilometry and holographic interferometry, stellar interferometry, etc., and the optical phase shift can be different. way to introduce. [0003] The general phase shift methods include piezoelectric ceramic (PZT) phase shift, grating phase shift, polarization phase shift and so on. For example, in the prior art (see G.E.Sommargren, D.W.Phillion, M.A.Johnson, et al, "100-picometer interferometry for EUVL", SPIE Vol.4688, 316-328, 2002), it is realized by devices such as beam splitters, PZTs, and corner cubes Phase shift f...

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Problems solved by technology

For example, in the prior art (see G.E.Sommargren, D.W.Phillion, M.A.Johnson, et al, "100-picometer interferometry for EUVL", SPIE Vol.4688, 316-328, 2002), it is realized by devices such as beam splitters, PZTs, and corner cubes Phase shift function, the phase shift is realized by piezoelectric ceramic PZT, and the structure is complex

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