Patent ID: 7982881

Claim:
An apparatus for interferometric measurement of a sample, comprising: a short-coherence interferometer arrangement, which comprises a measurement beam path through which a measurement beam is incident on the sample and returns from the sample; a first reference beam path, through which a first reference beam passes; at least one second reference beam path, through which a second reference beam passes and whose optical path length differs from that of the first reference beam path, the path length difference being selected according to a distance of two sample regions, which are spaced apart in depth direction of the sample; a superimposing device, which separates the measurement beam returned from the sample into a first and a second measurement beam part and separately superimposes the first measurement beam part upon the first reference beam and the second measurement beam part upon the second reference beam and then transmits the thus superimposed beams to a detector device for detection, wherein the superimposing device separates the measurement beam by dichroic separation and superimposes and transmits the superimposed beams spectrally separated and simultaneous to the detector device, and a control device connected to the detector device for determining from the detected, superimposed beams the distance between the sample regions by a Fourier spectral analysis in consideration of the path length difference of the reference beam paths.