DESCRIPTION OF A SINGLE MODULAR OPTICAL SETUP FOR ELLIPSOMETRY, SURFACE-PLASMONS, WAVE-GUIDE MODES, AND THEIR CORRESPONDING IMAGING TECHNIQUES INCLUDING BREWSTER-ANGLE MICROSCOPY

A versatile modular setup is described which incorporates ellipsometry , surface plasmon spectroscopy, waveguide modes, their corresponding i maging techniques and Brewster angle microscopy in a single instrument . The important design criteria are discussed with special emphasis gi ven to the requirements imposed by imaging under an oblique angle of i ncidence. Several experimental examples demonstrate the power of the i nstrument. Imaging nullellipsometry of a patterned monolayer on a high ly reflecting support demonstrates a lateral resolution of approximate ly 1 mu m and an accuracy in the thickness determination in the sub-nm region. The localization of the evanescent field of a surface plasmon was exploited to characterize adsorption layers in turbid and thus hi ghly scattering solutions. An example of how an anisotropic sample can be characterized with the aid of waveguide modes is provided. (C) 199 7 American Institute of Physics.