Vol 46, No 4 (2019)

The interaction between atoms placed into cavities of a one-dimensional photonic crystal (PC) and the radiation self-field is studied. Dispersion relations and photonic density of states for a one-dimensional PC consisting of gallium arsenide and vacuum layers in one case, and metamaterial and vacuum layers in the other case are calculated by the transition matrix method. Variations of the self-energy correction to the 1s state energy of the hydrogen atom are considered as functions of the optical contrast and relative thickness one-dimensional PC layers.

The dependence of the formation process of a light bullet on the relation between diffraction and dispersion lengths of the femtosecond mid-IR wave packet during its propagation in transparent dielectrics is studied. It is found that the ratio of the diffraction length of the wave packet to its dispersion length is the similarity parameter for the light bullet formation under conditions of anomalous dispersion of the group velocity. The value of the filamentation threshold power taken relative to the critical power of stationary self-focusing is also defined by the introduced similarity parameter and increases with it.

It is shown that optical injection can suppress unstable transverse modes, thus stabilizing broad-area laser emission. The general case of noncoinciding frequencies of injected radiation and laser emission is numerically studied. It is shown that the frequency noncoincidence does not degrade the stabilizing effect.

The sideband cooling method and its implementation on the Raman transition of ²⁵Mg⁺ is presented. The process is numerically simulated under the conditions of experiments at the Lebedev Physical Institute. Laser pulse parameters are optimized to achieve the minimum average vibrational number over the times of Raman cooling of the order of several milliseconds.

We present the results of the experimental formation of contour vortex fields, based on optics of spiral light beams with diffractive phase elements using binary amplitude—phase masks and phase holograms with symmetric and asymmetric grating line profiles. These methods are compared in diffraction efficiency and quality of obtained light fields.