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The use of computers and multimedia, as well as the World Wide Web and new communication technologies, allows new forms of teaching and learning like distance learning, blended learning, use of virtual libraries and many more. The herewith discussed RCL project shall offer an additional contribution. The basic idea is for a user to connect via the Internet with a computer from place A, to a real experiment carried out in place B. An overview of our technical and didactical developments as well as an outlook on future plans are presented. Currently, about 10 RCLs have been implemented. The essential characteristics of an RCL are the intuitive use and interactivity (operating the technical parameters), the possibility of different points of view of the ongoing experiment thanks to web cams, and the quickest possible transfer of the data measured by the user. A reasonable use of sensibly chosen real experiments as remote labs allows a new form of homework and exercises, as well as project work and the execution of experiments, which usually would a teacher's prerogative only.

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We have measured frequencies of all internal and external modes in natural and 32 S isotopically pure oriented orthorhombic single sulfur crystals using high-resolution Raman and FTIR spectroscopy. Polarized spectra at low temperatures deliver mode frequencies and allow mode assignment to vibrational, librational, and translational character. Experimental data, such as temperature dependent frequencies at constant volume, are analyzed in terms of anharmonic processes. In addition, frequency shifts at the lowest temperature due to isotopic impurities are qualitatively explained by a relative mass defect.

We have measured the temperature dependence of the infrared bandwidth of several lattice phonons and internal vibrons in natural and 32S isotopically pure orthorhombic sulfur crystals, using a high resolution FTIR interferometer. The experimental data were analyzed in terms of anharmonic phonon–phonon coupling processes and of contributions to the bandwidth due to the presence of randomly distributed isotopic impurities. The same three-phonon processes that contribute to the lifetime of the Raman bands were found to be active also for the infrared ones in the isotopically pure crystal. In parallel to the increase of the two-phonon density of states, the third-order anharmonic coupling coefficients for phonon decay processes were found to increase from the lowest to the highest lattice mode. The effect of the isotopic impurities was explained in terms of two contributions, the first, which is temperature independent, due to pure harmonic scattering processes and the second due to the combined effect of anharmonicity and scattering processes, which is instead dependent on the temperature. The contribution due to the presence of impurities was found to dominate the width of the lattice modes in the natural crystal at low temperatures. This purely harmonic contribution can be in some cases almost one order of magnitude larger than that due to the normal anharmonic decay processes in the isotopically pure crystal. Only the width of the factor group component of infrared and Raman vibrons close to the frequency of the isolated molecule was found to be affected by the presence of impurities through a resonant scattering mechanism.

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Remotely controlled laboratories are real experiments that can be controlled by users from their computers via the Internet. We present an overview of technical and pedagogical developments, describe the diversity and potential of our experiments, and comment on their acceptance by physics instructors.