Patent ID: 8687199
Filing Date: 2014-04-01
Classification: G01B,G01F,G02B

Abstract:
1. Deflection measuring device according to the interferometer principle, comprising: a radiation source, a first fiber-optic means for forming a first light path, a second fiber-optic means for forming a second light path, a deflection body and an evaluation circuit, wherein the first fiber-optic means and the second fiber-optic means are parts of a multi-core optical fiber, wherein said deflection body comprises a membrane; wherein the first fiber-optic means and the second fiber-optic means are positioned to be impinged with interference-capable radiation from the radiation source on an input side, wherein at least the first fiber-optic means is connected to the deflection body, wherein the multi-core fiber has a flattening that is positioned against the deflection body with the flattening having a fixed orientation relative to cores of the multi-core fiber, the cores being arranged one above the other perpendicular to the flattening causing said first fiber-optic means and said second fiber-optic means to experience different deflections due to deflection of said deflection body, wherein a first partial radiation beam guided in the first fiber-optic means and a second partial radiation beam guided in the second fiber-optic means are connected on an output side in a manner causing interference radiation to be conveyed to the evaluation circuit and evaluated by the evaluation circuit, wherein the first fiber-optic means and the second fiber-optic means are arranged only on the deflection body, wherein the first fiber-optic means and the second fiber-optic means are directly connected on the input side to the radiation source with a single feed optical fiber, wherein the single feed optical fiber has a light-guiding cross section that is large enough at an input-side junction to at least partially cover simultaneously both the light-guiding cross section of the first fiber-optic means and the light-guiding cross section of the second fiber-optic means, wherein said single feed optical fiber couples radiation into the first fiber-optic means and the second fiber-optic means, wherein said evaluation optical fiber has a light-guiding cross section that is large enough at an output-side junction to at least partially cover simultaneously both the light-guiding cross section of the first fiber-optic means and the light-guiding cross section of the second fiber-optic means, wherein said evaluation optical fiber decouples radiation out of the first fiber-optic means and the second fiber-optic means, wherein the first fiber-optic means and the second fiber-optic means are directly connected on the output side to the evaluation circuit with a single evaluation optical fiber, wherein the first fiber-optic means and the second fiber-optic means are positioned close enough to one another to enable crosstalk of the partial radiation beam guided along each of the fiber-optic means to the other of fiber-optic means, wherein the crosstalk between the first fiber-optic means and the second fiber-optic means is obtained by means of guided evanescent parts of the partial radiation guided outside of at least one of the first fiber-optic means and the second fiber-optic means, wherein the feed optical fiber and the evaluation optical fiber are formed each of a single-core optical fiber, and wherein the distance between said first fiber-optic means and said second fiber-optic means is less than 10 wavelengths of the guided partial radiation.