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The project deals with local probing of disordered materials by means of optical spectroscopy of impurity molecules. It consists of three main parts. First, theoretical approaches are developed for description of the microscopic frequency spread induced by the inhomogeneous matrix. The frequency dependencies of the coupling strength to local phonons, the pressure and the electric field effects will be treated in terms of intermolecular Lennard-Jones potentials. Second, the experimental part embraces the preparation of different guest-host systems and their complex spectroscopic investigation with the aim to verify theoretical predictions. The spectral behavior is characterised as a function of temperature, pressure and electric field in the broadest possible range of parameter variation. The measurements will be focussed on biologically and technologically relevant materials. Methods will be elaborated for nanoscale probing of atomic packing densities, local compressibility, electric cavity field and local vibrational modes, as well as for determination of intermolecular force constants and effective masses. The possibilities of optical spectroscopy will be tested on Geometrinae green wing pigments whose structure is still unknown, and their complexes with proteins. Finally, as a practical task, the sensitivity of geoverdin and other pigments with respect to ambient moisture will be exploited for developing laser optical sensors of humidity. |