Memeasuring a cavity by means of interference spectroscopy

A device for interferometric determination of geometric and/or optical parameters of a cavity, exhibiting:

• a tuneable coherent light source,
• a beam splitter for splitting light emitted by the tuneable coherent light source into a target beam and a reference beam,
• a first optical coupler for coupling the target beam into a target interferometer, which is bounded by the optical coupler and a moving object and exhibits a length x to be determined,
• a detector for frequency-resolved detection of an interference signal I(f) generated through superimposition of the reference beam on the target beam and for acquiring an interference spectrum of the interference signal I(f) over a frequency range Δf of a frequency f of the tuneable coherent light source,
• an analysing unit configured for analysing a plurality of measurement points of the acquired interference spectrum over the frequency range Δf through numerical fit of the measurement points to a generated mathematical function, and for determining the geometric and/or optical parameters of the cavity by ascertaining parameters of the generated mathematical function.