We present two different white-light spectral interferometric techniques to measure birefringence dispersion in two different elliptical-core polarization-maintaining fibers (PMFs). The first method is based on application of a lateral point-like force on a fiber under test and resolution of the spectral interference fringes and is used for measuring the wavelength dependence of the phase modal birefringence. The second method employs a Michelson interferometer that compensates the differential group optical path difference in the tandem PMF and is used for measuring the wavelength dependence of the group modal birefringence. The second method is also utilized for determining the sign of the group modal birefringence.

A white-light spectral interferometric technique employing a Michelson interferometer with same metallic mirrors is used to measure the effective thickness of a beamsplitter cube. The thickness is measured for four different beamsplitters being in two different orientations. Moreover, it is revealed that the phase function of a thin-film structure measured by a similar interferometric technique depends on the path length difference adjusted in the Michelson interferometer. This phenomenon is due to a dispersion error of a beamsplitter cube, the effective thickness of which varies with the adjusted path length difference. A technique for eliminating the effect in measurement of the phase function is described. First, the effective thickness of the beamsplitter cube as a function of the path length difference is measured. Second, the phase function of the thin-film structure is measured for the same path length differences as those adjusted in the first case. In both cases, the phase is retrieved from the recorded spectral interferograms by using a windowed Fourier transform applied in the wavelength domain.

We present a simple white-light spectral-domain technique based on tandem interferometry that employs a low-resolution spectrometer for a direct measurement of the group dispersion of optical components over a wide wavelength range. The technique utilizes a tandem configuration of a Michelson interferometer and an unbalanced Mach-Zehnder interferometer with a component under test inserted into one arm and the other arm with adjustable path length. We resolve the spectral interference fringes when suitable path length difference is adjusted in both interferometers. From the recorded spectral interference signals, the equalization wavelength is determined for which the overall group optical path difference between the beams is zero. By measurement of the equalization wavelength as a function of the path length difference adjusted in the Mach-Zehnder interferometer, the group dispersion of a glass sample is determined and agreement is confirmed with measurement using a Michelson interferometer only.