Extending the scope of spectrum-controlled interferometry by superposition of multiple spectral modulations

摘要

The measurement range in the spectrum control interferometry (SCI) is extended by superimposing a plurality of modulations (F1, F2) on the low coherence light used for the measurement. Optimally, a spectrally controllable light source (16) sinusoidally modulated at a low spectral frequency is combined with a delay line (18) provided by a Michelson interferometer. The resulting light is incident on a Fizeau interferometer (10) and localized interference fringes at a distance corresponding to the effect of the spectrally modulated light source combined with the optical path difference created by the delay line (18). Generate This combination provides a convenient way to implement SCI, extending all the benefits of SCI and the measurement range to the extent required for practical and foreseeable applications. [Selection diagram] Fig. 4