Abstract

The technology of surface light scattering spectroscopy¹ involves hardware issues in measuring accurately the surface elevation ζ_q(t), autocorrelation function ${\text{R}}_{\text{q}}(\text{t})\underset{¯}{\underset{¯}{\text{def}}}〈{\zeta }_q^{*}(0){\zeta }_q(\text{t})〉$ or the corresponding spectrum, ${\text{G}}_q(\omega )=\widehat{F}\left(〈{\varsigma }^{*}{}_q(0){\varsigma }_q(t)〉\right)[\omega ]$ where q is the wave number of the capillary wave spectrum and ω the frequency. Major issues include the optimization of the optical signal to noise, minimization of environmental noise and deconvolution of R_q(t) from the instrument function. This last issue is of special interest when measuring scattering from small patches wherein qσ < 20, σ is the Gaussian beam width parameter, as is the case when used with Brewster angle microscopy in overlapping footprints.

© 1996 Optical Society of America