We have studied stimulated emission in a random laser based on rhodamine 6G dye and TiO2 nanoparticles. At both small and large concentrations of nanoparticles, the minimum threshold was found at ultra-high concentrations of dye, 20 g L−1. With the increase in concentration of TiO2 nanoparticles, the threshold reaches its maximum at the transition from a weak-scattering regime to a strong-scatt...

Heavy quark physics is one of the frontier areas in studies of the fundamental properties of matter. That is why a new generation of ee colliders (B-factories) has been designed. The CLEO-III , BELLE , and BABAR 3 experiments are running since 1999. Their main goal is the precise investigation of the CabibboKobayashi-Maskawa matrix and, first of all, CP-violation in the b-quark sector. To achie...

We demonstrate a new type of weak measurement based on the dynamics of spontaneous emission. The pointer in our scheme is given by the Lorentzian distribution characterizing atomic exponential decay via emission of a single photon. We thus introduce weak measurement, so far demonstrated nearly exclusively with laser beams and Gaussian statistics, into the quantum regime of single emitters and s...

Several BL Lac objects are confirmed sources of variable and strongly Dopplerboosted TeV emission produced in the nuclear portions of their relativistic jets. It is more than probable, that also many of the FR I radio galaxies, believed to be the parent population of BL Lacs, are TeV sources, for which Doppler-hidden nuclear γray radiation may be only too weak to be directly observed. Here we s...

Optical microscopy has enabled in vivo monitoring of brain structures and functions with high spatial resolution. However, the strong optical scattering turbid tissue skull impedes observation microvasculature neuronal at a large depth. Herein, we proposed strategy to overcome influence induced by effect both via combination clearing (SOC) technique three-photon fluorescence (3PM). The visible-...

An extended Bose-Einstein condensate (BEC) in an optical lattice provides a kind of periodic dielectric and causes band gaps to occur in the spectrum of light propagating through it. We examine the question whether these band gaps can modify the spontaneous emission rate of atoms excited from the BEC, and whether they can lead to a self-stabilization of the BEC against spontaneous emission. We ...

Several lines of evidence point to a relationship between gamma-ray bursts (GRBs) and the high mass stars that explode as supernovae. Arguments that GRB sources accelerate cosmic rays (CRs) are summarized. High-energy neutrino detection from individual GRBs would mean that they are hadronically dominated, that is, that the amount of energy deposited in the form of nonthermal hadrons in GRB blas...

Nonlinear excitation of fluorophores through molecular absorption of two or three near-infra-red photons from the tightly focused femtosecond pulses of a mode-locked laser offers the cellular biologist an unprecedented panoply of biomolecular indicators for microscopic imaging and cellular analysis. Measurements of the two-photon excitation spectra of 25 ultra-violet and visible absorbing fluor...

We study a large ensemble of nuclear spins interacting with a single electron spin in a quantum dot under optical excitation and photon detection. At the two-photon resonance between the two electron-spin states, the detection of light scattering from the intermediate exciton state acts as a weak quantum measurement of the effective magnetic (Overhauser) field due to the nuclear spins. In a coh...

Targets located at the same distance are easily neglected in most through-wall multiple targets detecting applications which use the single-input single-output (SISO) ultra-wideband (UWB) radar system. In this paper, a novel multiple targets vital signs tracking algorithm for through-wall detection using SISO UWB radar has been proposed. Taking advantage of the high-resolution decomposition of ...