Investigation of clouds spatial distribution using ground-based lidar

Certain investigations of spatial distribution of clouds by employing ground based lidar are presented. The great changeability is one of the main properties of the clouds in the boundary layer. As a result, their optical properties change rapidly which complicates the modeling of cloud evolution. Suitable equipped lidars are widely used for diagnostics of the clouds via a number of scattering and absorption processes. In particular, lidar can provide information on the distribution of meteorological parameters and of the other important cloud characteristics both in vertical and horizontal directions. Herein the time and spatial distribution of the aerosol backscattering coefficient of S sub t and S sub c type clouds are investigated by means of a correlation analysis of the lidar obtained data provided from several arbitrary directions and heights

Introduction to the special issue on biophotonics - Part 2

The 30 articles in this special section cover a broad range among the following areas: advanced bioimaging; multifunctional endoscopy; novel approaches in biophotonic diagnostics and therapeutics; advanced biophotonic sensing techniques; laser-cell interactions; photoacoustics and terahertz biophotonics; nanobiophotonics; and novel laser, fiber-optics and electrooptics biophotonic tools, and devices

Photoionization-Induced Emission of Tunable Few-Cycle Midinfrared Dispersive Waves in Gas-Filled Hollow-Core Photonic Crystal Fibers

We propose a scheme for the emission of few-cycle dispersive waves in the mid-infrared using hollow-core photonic crystal fibers filled with noble gas. The underlying mechanism is the formation of a plasma cloud by a self-compressed, sub-cycle pump pulse. The resulting free-electron population modifies the fiber dispersion, allowing phase-matched access to dispersive waves at otherwise inaccessible frequencies, well into the mid-IR. Remarkably, the pulses generated turn out to have durations of the order of two optical cycles. In addition, this ultrafast emission, which occurs even in the absence of a zero dispersion point between pump and mid-IR wavelengths, is tunable over a wide frequency range simply by adjusting the gas pressure. These theoretical results pave the way to a new generation of compact, fiber-based sources of few-cycle mid-IR radiation.Comment: 5 pages, 4 figure