Simple null polarimetry is introduced to measure the refractive index n of transparent and semitransparent materials. For a linearly polarized incident light, the reflected polarization can be used to determine n with the Fresnel equations. This method is fast, convenient, and versatile enough to provide accurate results on small laboratory samples. Possible errors in experiments are analyzed, and ways to eliminate these errors are given. With our instrument, the uncertainty in the deduced n is ±0.0004. The accuracy is still within 0.1% for materials with high n and with the extinction coefficient of the order of 0.001. The method is also sufficiently accurate for characterizing the homogeneity of transparent materials.
© 1993 Optical Society of America
Original Manuscript: December 14, 1992
Manuscript Accepted: March 15, 1993
Published: September 1, 1993
S. F. Nee and H. E. Bennett, "Accurate null polarimetry for measuring the refractive index of transparent materials," J. Opt. Soc. Am. A 10, 2076-2083 (1993)