Spectral-domain interference of two beams from a white-light source is analyzed theoretically and experimentally when the effects of both dispersion in an interferometer and the response function of a, spectrometer are taken into account. The spectral interference law is expressed analytically under the condition of a Gaussian response function of a spectrometer. It is revealed that the spectral interference fringes can be resolved, visibility of which depends on the bandpass of the spectrometer and on the group optical path difference (OPD) between interfering beams. The theoretical analysis is accompanied by experiments employing a dispersive Michelson interferometer and a low-resolution Spectrometer. Two experiments with different amounts of dispersion in the Michelson interferometer are realized giving the spectral interference fringes resolved only in the vicinity of the so-called equalization wavelength, at which the group OPD between interfering beams is zero. The spectral interferograms recorded within both experiments are compared with the theoretical ones, which are modeled knowing dispersion in the interferometer and the bandpass of the spectrometer. Dispersion in the interferometer is affected by the thickness of the optical sample made of fused silica and the refractive index dispersion governed by the Sellmeier dispersion relation. It is revealed good agreement between the theory and experiment indicating a possibility of proposing a new method of measuring distances and displacements when dispersion in the interferometer is known.

Date Published: 21 November 2003
PDF: 8 pages
Proc. SPIE 5259, 13th Polish-Czech-Slovak Conference on Wave and Quantum Aspects of Contemporary Optics, (21 November 2003); doi: 10.1117/12.545150

Published in SPIE Proceedings Vol. 5259:
13th Polish-Czech-Slovak Conference on Wave and Quantum Aspects of Contemporary Optics
Jerzy Nowak; Marek Zajac; Jan Masajada, Editor(s)