Compact construction of a Michelson interferometer for the measurement of changes in length and in refractive index

摘要

In comparison with previously used classical interferometers, this invention is distinguished by its miniaturised, simple, compact design, which, furthermore, reduces the calibration effort, which is considerable in a conventionally constructed Michelson interferometer, for the alignment of the measuring mirror. The light is guided in single-mode waveguides which are produced by means of structured ion exchange in glass substrates or diffusion into crystals. The beam-splitter is realised optically integrated by means of a symmetrical coupler. Beam-splitter, reference arm and reference mirror lie protected in the substrate. The interferometer is thereby insensitive to vibrations and electromagnetic interference radiation. The invention can be applied anywhere where the physical quantity to be measured industrially effects an alteration of the optical path.