Surface fluctuation spectroscopy by surface-light-scattering spectroscopy

In recent years surface-light-scattering spectroscopy has been transformed from a complex optical experiment requiring substantial effort to operate e ffectively to a simpler instrument for which an accurate theory of operatio n has been developed. The accuracy and precision are sufficiently enhanced that refinement of the theory of spectral band shapes is justified to inclu de more subtle effects such as bending moduli and thin-film forces associat ed with the van der Waals and the Casimir effects. We show how to develop e xtensions of the theory of interfacial fluctuations through the mass and th e momentum balances of interfacial transport. We also show that free-energy functionals can be used to express curvature effects crisply. The results are detailed formulas that can be used to fit experimental spectra. (C) 200 1 Optical Society of America.