We report on a technique for measuring the refractive indices of nonabsorbing media over a broad spectral range from 0.5 to 5 μm. White-light interferometry based on a double-interferometer system consisting of a fixed Mach-Zehnder interferometer and a Fourier-transform spectrometer is used for direct measurement of the absolute rotation-dependent phase shift induced by an optical element. Refractive index <i>n</i>(λ) over the whole investigated spectral range is thus obtained directly to an accuracy of 10<sup>−4</sup> without the need for any specific assumption about dispersion. Results for synthetic fused silica are presented and discussed.
© 2003 Optical Society of America
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(120.4530) Instrumentation, measurement, and metrology : Optical constants
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
(260.2030) Physical optics : Dispersion
Matteo Galli, Franco Marabelli, and Giorgio Guizzetti, "Direct Measurement of Refractive-Index Dispersion of Transparent Media by White-Light Interferometry," Appl. Opt. 42, 3910-3914 (2003)