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Ellipsometry is a sensitive and noninvasive technique for the characterization of thin films. A recently developed ellipsometer, based on the four-detector photopolarimeter, was arranged outside a UHV chemical vapor deposition chamber for the in situ monitoring of film growth processes. The instrument showed a sensitivity in the submonolayer range when used to follow the growth of germanium thin films deposited on silicon substrates. As the main instrument drawback is represented by the need to have precise alignment, an effective positioning procedure was developed to obtain a positioning error smaller than 0.1°.

We propose ellipsometer configurations where, by conveniently modulating either the input or the output polarization, one can determine the ellipsometric parameters, D and psi, purely from phase measurements on two harmonic components of the signal from a single detector. Such phase measurements are less sensitive to noise than the conventional amplitude measurements, and the proposed modulation techniques can allow the achievement of frequencies up to tens of megahertz. Thus a very good time resolution is achieved.

At the Transparent Materials Laboratory of the Italian Agency for Energy, New Technologies and Environment, the characterization of advanced transparent materials (CATRAM) facility permits the optical characteristics of transparent advanced materials to be evaluated, a procedure for which spectrophotometers are not adequate. The CATRAM facility is based mainly on a large-diameter integrating sphere to perform transmittance, reflectance, and absorptance measurements. We describe the measurement procedures and verify the reliability of the facility by comparing the results obtained for several samples with those from other laboratories. Furthermore, some system implementations for improvement of accuracy are discussed.

Generally CCl(4) is used in photothermal deflection spectroscopy as the deflecting medium. We looked for alternative deflecting liquids. This Letter reports the main features of some suitable liquids.