Study of some coherent processes involving nonlinear interactions of light with matter

Milivoj R. Belić

Philip St.J. Russell

Physical processes involving light-matter interactions can be enhanced by confining light in a small volume, for example in a three-dimensional resonator or a narrow channel waveguide. The intensity (or energy density) achievable for a given power (or energy) is enhanced, increasing the effective nonlinearity.

Marina Ţurcan

It is particularly important by now to apply the coherent light proprieties in process control from biomolecular system. In this way, the present report has two basic aspects of the interaction of light with the substance are discussed: the nonlinear one of light interaction with the environment, and the cooperative aspect of interaction of photons with matter in specially biomolecules. Another goal of this work is the presentasions and analysys oh the hydrogen bonds between the Guanine - Cytosine (G-C) and behavior of these nucleotide during the Raman processes. Developed on the basis of experimental evidence, the model incorporates the local symmetry inherent in biomolecular structures. The photons transformation and statistic is presented for the control in the biomolecular systems.

Chuan‐Cun Shu, Daoyi Dong, Ian R. Petersen +1 more

The absorption of a single photon that excites a quantum system from a low to a high energy level is an elementary process of light-matter interaction, and a route towards realizing pure single-photon absorption has both fundamental and practical implications in quantum technology. Due to nonlinear optical effects, however, the probability of pure single-photon absorption is usually very low, which is particularly pertinent in the case of strong ultrafast laser pulses with broad bandwidth. Here we demonstrate theoretically a counterintuitive coherent single-photon absorption scheme by eliminating nonlinear interactions of ultrafast laser pulses with quantum systems. That is, a completely linear response of the system with respect to the spectral energy density of the incident light at the transition frequency can be obtained for all transition probabilities between 0 and 100% in multilevel quantum systems. To that end, a multiobjective optimization algorithm is developed to find an optimal spectral phase of an ultrafast laser pulse, which is capable of eliminating all possible nonlinear optical responses while maximizing the probability of single-photon absorption between quantum states. This work not only deepens our understanding of light-matter interactions, but also offers a way to study photophysical and photochemical processes in the ``absence'' of nonlinear optical effects.

Ralf Menzel