Optics of Langmuir-Blodgett films: Are two-dimensional systems unique?

We investigated the optical properties of two-dimensional systems using the Langmuir-Blodgett films with a particular attention to find if two dimensional systems behave optically in any different manner than ordinary three-dimensional materials. A simple and comprehensive way to relate the microscopic optical constants of array of point-dipoles to the macroscopically measured quantities is presented and the resulting absorption spectrum is favorably compared with that of the experiment. The reflection spectrum, on the other hand, shows a signature that may reveal features hidden in the absorption spectra, the interpretation of which is still to be worked out.