Ellipsometry with randomly varying polarization states

Abstract

Abstract:We show that, under the right conditions, one can make highly accurate polarization-based measurements without knowing the absolute polarization state of the probing light field. It is shown that light, passed through a randomly varying birefringent material has a well-defined orbit on the Poincar sphere, which we term a generalized polarization state, that is preserved. Changes to the generalized polarization state can then be used in place of the absolute polarization states that make up the generalized state, to measure the change in polarization due to a sample under investigation. We illustrate the usefulness of this analysis approach by demonstrating fiber-based ellipsometry, where the polarization state of the probe light is unknown, and, yet, the ellipsometric angles of the investigated sample (Ψ and Δ) are obtained with an accuracy comparable to that of conventional ellipsometry instruments by measuring changes to the generalized polarization state. 373-376 (2000). 6. K. Prime and G. Whitesides, "Self-assembled organic monolayers -model systems for studying adsorption of proteins At surfaces," Science 252(5009), 1164-1167 (1991). 7. J. Xue, C. Jung, and M. Kim, "Phase-transitions Of liquid-crystal films on an air-water-interface," Phys. Rev.Lett. 69(3), 474-477 (1992). 8. G. Rikken and E. Raupach, "Observation of magneto-chiral dichroism," Nature 390(6659), 493-494 (1997). 9. A. H. Gnauck, G. Charlet, P. Tran, P. J. Winzer, C. R. Doerr, J. C. Centanni, E. C. Burrows, T. Kawanishi, T. Sakamoto, and K. Higuma, "25.6-Tb/s WDM transmission of polarization-multiplexed RZ-DQPSK signals,"