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 effectively to a simpler instrument for which an accurate theory of operation has been developed. The accuracy and precision are sufficiently enhanced that refinement of the theory of spectral band shapes is justified to include more subtle effects such as bending moduli and thin-film forces associated with the van der Waals and the Casimir effects. We show how to develop extensions of the theory of interfacial fluctuations through the mass and the 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) 2001 Optical Society of America.