Patent ID: 8678594

Claim:
Spectral interferometry apparatus comprising: an optical source; an interferometer configuration having at least an interferometer equipped with at least two optical paths, having an interferometer output, wherein the optical spectrum at the interferometer output is modulated, with modulation depending on the optical path difference (OPD) in the interferometer; a spectral interrogator configuration equipped with at least a spectral interrogating unit, for the spectrum at the output of the interferometer which reads the spectrum with a periodicity 1/F and delivers a measuring signal to an electronic processing unit which provides a variable signal with a dominant single frequency in response to the modulation of the optical spectrum, to an indicating means, where the indicating means provides an indicating signal in the form of an audio signal, of a luminous signal, or a combination of both; wherein at least a characteristic of the indicating signal provides a measurement of a single OPD value in the interferometer configuration.