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The Raman scattering of Cisplatin (the first generation of anticancer drugs) has been studied. In the presence of silver nanoparticles, strong modifications of Raman spectra have been observed. The Raman frequencies have been shifted and the line profiles are broadened. We develop a theoretical model to explain the observed features of the Raman scattering. The model takes into account self-consistently the interaction of molecules with surface plasmonic waves excited in the silver nanoparticles, and it provides a qualitative agreement with the observed Raman spectra. We have demonstrated that the using silver nanoparticles can increase sensitivity of the technique, and potentially it has a broader range of applications to both spectroscopy and microscopy.

We consider the motion of a quantum particle in a free space. Introducing an explicit measurement procedure for velocity, we demonstrate that the measured velocity is related to the group and phase velocities of the corresponding matter waves. We show that for long distances the measured velocity coincides with the matter wave group velocity. We discuss the possibilities to demonstrate these effects for the optical pulses in coherently driven media or for radiation propagating in waveguides.

We investigate cooperative emission from a rubidium vapor, and demonstrate a controlled transition from yoked superfluorescence to three-photon-induced superradiance by driving the medium with co-propagating ultrashort laser pulses. We study temporal emission profiles and time delays on a picosecond time scale and compare the measured pulse shapes with simulations. Our results suggest strategies to improve efficiency of mirrorless lasers and superradiant light sources.

We have studied the intensity correlations between two orthogonally linearly polarized components of a laser field propagating through a resonant atomic medium. These experiments have been performed in a rubidium atomic vapor. We observe that the correlations between the orthogonally polarized components of the laser beam are maximal in the absence of a magnetic field. The magnitude of the correlations depends on the applied magnetic field, and the magnitude first decreases and then increases with increasing magnetic field. Minimal correlations and maximal rotation angles are observed at the same magnetic fields. The width of the correlation function is directly proportional to the excited state lifetime and inversely proportional to the Rabi frequency of laser field.

Maximizing the molecular response to coherent anti-Stokes Raman spectroscopy (CARS) requires optimizing the preparation of a vibrational quantum coherence. We simulate the amount of laser-induced coherence prepared in a three-level system modeled after dipicolinic acid (DPA), a marker molecule for bacterial spores. The level spacings and decoherence times were chosen to agree with experimental data observed from DPA. Nearly-maximal vibrational coherences can be induced for 150 fs optical pulses, despite the very fast dephasing rates of the electronic transitions. It is also shown that pulse propagation effects play an important role in the development of coherence throughout an extended sample, due to nonlinear index effects of the molecule at the laser frequencies.

We introduce the scattering problem in the case of one-dimensional space. The transmission factor is calculated for the whole domain of the potential energy. Connection with a field in interaction with a two-level quantum system is established for which the coupling parameter is considered to be explicitly time-dependent.

We give a comparative analysis of basic schemes of optical control of Mossbauer spectra providing an elimination of resonant absorption by a gamma-ray nuclear transition and suggest a novel scheme of frequency non-selective optical pumping which turns out to be the most promising for a realization of induced gain in the gamma-ray range.

A novel configuration of quantum nondemolition (QND) measurement of optical intensity of an electromagnetic (EM) wave via wave coupling in a nonlinear heterostructure is suggested. An example of such a measurement for a heterostructure formed by spatially modulated density of cascade-type three-level atoms is considered.