Investigation of slow light enhanced nonlinear transmission for all-optical regeneration in silicon photonic crystal waveguides at 10 Gbit/s

We demonstrate bit error rate improvement, corroborated by eye diagram measurements, of a (10 MHz) amplitude distorted 10 Gbit/s data signal in silicon photonic crystal waveguides. This demonstration exploits a power clamping nonlinear transfer function, provided by slow light enhancement of nonlinear absorption in these waveguides.     

Hopping on a zig-zag course

We study the diffusion coefficient of Active Brownian particles in two dimensions. In addition to usual attributes of active motion we let the particles turn in preferred directions over random times. This angular motion is modeled by an effective Lorentz force with time dependent frequency switching between two values at exponentially distributed random times. The diffusion coefficient is calculated by the Taylor-Kubo formula where distributions found from a Fokker-Planck equation or from a continuous time random walk approach have been inserted for averaging. Eventually properties of the diffusion coefficient will be discussed.     

Single axial mode pumping and external mirror operation of a pulsed spin-flip Raman laser at 10.6 μm

By the addition of an external cavity to a single axial mode, TEA CO₂ laser pumped, In Sb spin-flip Raman laser, a tenfold increase in first Stokes output and a twenty-five fold increase in second Stokes and anti-Stokes outputs has been observed.     

Metal atom-induced diffuse scattering from short-range order among deuterium atoms in single crystal α-phase V2D

X-ray scattering has been studied above the critical ordering temperature, T_c (133°C), in b.c.c. α-phase V₂D. At 140 and 200°C quite weak diffuse intensity was observed centered on the reciprocal lattice points of the ordered superlattice. This intensity is due to short-range order among deuterium atoms which induces a local or short-range modulation of the parent vanadium lattice and suggests the possibility of local octahedral D—D fluctuations building up well above T_c.     

Critical point wetting in NbH0.31

The local α-α' phase distribution in a thin Nb single crystal loaded with the critical H-concentration was investigated with X-rays. The sample used in the experiment showed a macroscopic hydrogen density mode, leading to a curvature of the whole crystal plate with the α-phase on the concave side and the α'-phase on the convex side. In addition an α-phase wetting layer was found on top of the α'-phase separated from the bulk α'-phase by a mixed α-α' phase region. In a simple model their thickness were determined to about $\text{\$}\text{?}$1.0 and 7?0μm, resp. This thin wetting layer leads to a new interpretation of the phase transition of H and Nb, involving the familiar long-range elastic interaction as well as a short-range surface free energy contribution.     

A phase I, randomized study of combined IL-2 and therapeutic immunisation with antiretroviral therapy

Background  

Fully functional HIV-1-specific CD8 and CD4 effector T-cell responses are vital to the containment of viral activity and disease progression. These responses are lacking in HIV-1-infected patients with progressive disease. We attempted to augment fully functional HIV-1-specific CD8 and CD4 effector T-cell responses in patients with advanced chronic HIV-1 infection.