[en] The properties of diamond-like carbon (DLC) films can vary widely from graphite (sp² local bonding) to diamond (sp³ local bonding), strongly depending on the film preparation conditions. As the optical constants (n,k) of sp³ bonded carbon are quite different from those of sp² bonded carbon over the visible and near-infrared (VIS-NIR) spectral range, it is possible to provide precise quantitative information on sp³ C (sp² C) fractions using optical characterization methods. In the present work, spectroscopic ellipsometry (SE) using multiple sample analysis method has been applied to study a series of DLC films on silicon substrates prepared by filtered arc deposition (FAD) technique. In contrast to most reported SE studies, the DLC film was simulated by a mixture of sp³ C, sp² C and void constituents instead of treating it as a whole. From the interpretation of SE spectra, the film thickness and the volume fractions of sp³ C, sp² C and void have been derived, respectively. In addition, comparison between SE results and Rutherford backscattering spectroscopy (RBS) and electron energy loss spectroscopy (EELS) results will be given. This work shows that SE using multiple sample analysis method is a very useful optical method to determine sp³ C fractions in DLC films