Fig. 1.

Schematic representation of the interferometric experimental configurations are shown along with examples of measured spectra for each technique. (Left) WL reflection spectroscopy is based on spectral variations of reflection from thin transparent films. Interference of light reflected from the top surface and a buried reference surface results in periodic oscillations. (Right) The SSFM technique maps the spectral oscillations emitted by a fluorophore located on a layered reflecting surface into a precise position determination. Analysis of the spectral oscillations (using a grating spectrometer) due to the self-interference from the direct and reflected emission yields the vertical position of that fluorophore with subnanometer accuracy.