Device and reflectometry method has low coherence detection time-frequency

The present invention relates to a device or apparatus low coherence interferometer (100, 200) for determining information about the structure and / or location of an object interfaces (13) comprising: a light source (11) polychromatic; an optical system for generating an optical measuring beam and a reference optical beam; a delay line (14) for introducing a variable optical delay between the optical measurement beam and the reference optical beam; an optical detecting means (15) for combining the optical measurement beam and the reference optical beam and producing a representative spectral signal of a spectral power density of the resulting optical interference signal; a control and processing module (16) arranged to acquire a plurality of spectrum signals to a plurality of optical delays, determining for each spectral signal information optical delay between interfering beams in a range of said spectral measurement, analyze the changing said optical delays according to the optical delay, and to deduce therefrom information on the structure and / or location of the object interfaces (13). The invention also relates to a method implemented in the device or apparatus.