We present an experimental demonstration of the spectral interference phenomenon, using a spectrally broad white-light source in a Michelson interferometer configuration. We also present a theoretical analysis of the spectral interference law for the general case of amplitude-division interferometers. When a dispersive medium is introduced into one of the arms of the interferometer, the spectral interference pattern changes drastically, with a change in the frequency modulation corresponding to the dispersive nature of the medium. A zero-order fringe appears at a wavelength where the net path difference between the two arms of the interferometer is zero. We relate the thickness of the dispersive medium to the width of the zero-order fringe. From the experimental data over the entire visible region of the spectrum we obtain the refractive index n(λ) and the thickness t of the dispersive medium, calculated to an accuracy of the order of 10−5.
© 1995 Optical Society of America
V. Nirmal Kumar and D. Narayana Rao, "Using interference in the frequency domain for precise determination of thickness and refractive indices of normal dispersive materials," J. Opt. Soc. Am. B 12, 1559-1563 (1995)