Direct measurement of refractive-index dispersion of transparent media by white-light interferometry.
We report on a technique for measuring the refractive indices of nonabsorbing media over a broad spectral range from 0.5 to 5 microm. 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 n(lambda) over the whole investigated spectral range is thus obtained directly to an accuracy of 10(-4) without the need for any specific assumption about dispersion. Results for synthetic fused silica are presented and discussed.
Galli
Matteo
M
Dipartimento di Fisica A. Volta, Istituto Nazionale di Fisica delle Materia, Università degli Studi di Pavia, Via Bassi 6, I-27100 Pavia, Italy. galli@fisicavolta.-unipv.it
Marabelli
Franco
F
Guizzetti
Giorgio
G