Whispering gallery modes in optical fibers based on reflectionless potentials

We consider an optical fiber with nanoscale variation of the effective fiber radius supporting whispering gallery modes slowly propagating along the fiber, and reveal that the radius variation can be designed to support reflectionless propagation of these modes. We show that reflectionless modulations can realize control of transmission amplitude and temporal delay, while enabling close packing due to the absence of cross-talk, in contrast to conventional potentials.Comment: 4 pages, 3 figure

Harmonic generation enhancement due to interaction of few-cycle light pulses in nonlinear dielectric coating on a mirror

We theoretically investigate reflection of a few-cycle light pulse from a mirror with nonlinear dielectric coating. We employ a nonlinear equation that describes spatiotemporal evolution of a few-cycle light pulse with a broad spectrum that lies in the transparency range of nonlinear dielectric media. This model is formulated directly for the electric field without slowly varying amplitude approximation. Analytical and numerical analysis shows that counter-propagating wave interactions in thin films can strongly enhance or suppress third harmonic generation of the central frequency, whereas this effect is neglected in the framework of slowly varying amplitude approximation

Editorial: Fruit and seed evolution in angiosperms

The diversity of fruits and seeds is enormous all over the world, and they play a crucial role in all aspects of biology, including human life. Despite the long history of carpological research, many characteristics of fruit and seed structure and evolution, as well as dispersal mechanisms, seed germination, and the ecological parameters of fruit and seed traits, have been lacking attention so far. Recently developed comparative methods based on molecular phylogeny and other new technologies provide an excellent opportunity for tracing the evolution of fruits and seeds in various plant groups

Coupling of Whispering Gallery Modes in Optical Fiber Resonators Based on Reflectionless Potential

Photonic platforms combining the benefits of microscopic dimensions, flexibility, and control are of great interest due to the present and anticipated breakthrough capabilities in optical computing and communications. It was recently demonstrated that high-quality-factor traps for photons can be created in an optical fiber with nanoscale variation of an effective fiber radius [1, 2], which can account for the modification of both the fiber radius as well as the medium refractive index. Such fiber resonators function as surface nanoscale axial photonics (SNAP) devices, supporting whispering gallery modes (WGMs) which circulate near the fiber surface and slowly propagate in axial direction. The SNAP platforms enable precise control over the mode characteristics thanks to the record breaking sub-angstrom fabrication precision and ultralow scattering losses

Frequency combs in nonlinear SNAP fiber resonators

We suggest Surface Nanoscale Axial Photonic fiber resonators for frequency comb generation, and show that precise control of the fiber radius can facilitate combs with ultrafine spacing beyond the fundamental limit of conventional ring resonator

Impaired Mitochondrial Function in T-Lymphocytes as a Result of Exposure to HIV and ART

Mitochondrial dysfunction is a described phenomenon for a number of chronic and infectious diseases. At the same time, the question remains open: is this condition a consequence or a cause of the progression of the disease? In this review, we consider the role of the development of mitochondrial dysfunction in the progression of HIV (human immunodeficiency viruses) infection and the onset of AIDS (acquired immunodeficiency syndrome), as well as the direct impact of HIV on mitochondria. In addition, we will touch upon such an important issue as the effect of ART (Antiretroviral Therapy) drugs on mitochondria, since ART is currently the only effective way to curb the progression of HIV in infected patients, and because the identification of potential side effects can help to more consciously approach the development of new drugs in the treatment of HIV infection

Permeability adjustment of polyelectrolyte micro-and nanocapsules by laser irradiation

Laser radiation was used for permeability increase up to destroy of polyelectrolyte capsules. Silver and gold nanoparticles was synthesized and incorporated into capsule shells to attain the sensitivity of microcapsules to laser radiation. Lasers of different power and wavelength were used. The sensitivity of nanocomposite shell to laser radiation can be controlled by nanoparticle shape, content and distribution into the shell