Focusing systems based on two-dimensional photonic crystals

Methods of focusing electromagnetic waves based on the use of two-dimensional photonic crystals formed by metal and dielectric elements are considered. In the first case the physical basis for the creation of radiation focusing systems consists in the manifestation of the properties of a homogeneous medium with ultra-low refractive index by metal photonic crystals at the frequencies of the first allowed zone. In the second case the possibility of constructive interference of direct transmission waves and edge waves diffracting at the edges of spatially bounded dielectric structures is used for focusing.

Unimolecular Reactions

This chapter considers unimolecular reactions; photo-induced reactions, that is, true unimolecular reactions; and reactions initiated by collisional activation, that is, apparent unimolecular reactions where it is assumed that the time scales for activation and subsequent reaction are well separated. Elements of classical and quantum dynamical descriptions are discussed, including Slater theory and the quantum mechanical description of photo-induced reactions. Statistical theories aiming at the calculation of micro-canonical as well as canonical rate constants are discussed, including a detailed discussion of RRKM theory. It concludes with a discussion of femtochemistry, that is, the observation and control of chemical dynamics using femtosecond pulses of electromagnetic radiation, focusing on the control of unimolecular reactions via the interaction with coherent light; that is, laser control.