Laser diode end-pumped cw BaLaGa3O7:Nd laser

Laser diode end pumped CW laser action in disordered crystal BaLaGa3O7:Nd (BLGO:Nd) has been investigated. Optical slope efficiency exceeding 50% has been recorded. The process of excited state absorption in this material has been discussed

Wide wavelength tuning of an optical parametric oscillator through electro-optic shaping of the gain spectrum

We present a novel technique for tuning an optical parametric oscillator (OPO) through electro-optically induced shape variations of the parametric gain spectrum in quasi-phase-matched lithium niobate (LN). The diode-pumped, triply resonant continuous-wave OPO is based on a 58-mm-long LN crystal that consists of three equally long sections, the outer sections being periodically poled with a 50% duty cycle. The center section is single-domain material and serves as a tunable phase shifter through the electro-optic effect. By application of a voltage of up to 1230 V, the OPO signal and idler wavelengths are tuned over 102 nm from 1560 to 1660 nm, in good agreement with theory

Grundlagen fuer den Einsatz miniaturisierter Lasersysteme im sichtbaren Spektralbereich. Teilvorhaben: Untersuchung der physikalisch-technischen Grundlagen von Hochleistungsdiodenlasern mit effizienter externer Frequenzverdopplung Abschlussbericht

SIGLEAvailable from TIB Hannover: F00B1119+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung (BMBF), Bonn (Germany)DEGerman

A geometric cascade for the spectral approximation of the Navier-Stokes equations

We explain some ideas contained in some recent papers, concerning the statistical long time behaviour of the spectral approximation of the Navier-Stokes equations, driven by a highly degenerate white noise forcing. The analysis highlights that the ergodicity of the stochastic system is obtained by a geometric cascade. Such a cascade can be interpreted as the mathematical counterpart of the energy cascade, a well-known phenomenon in turbulence. In the second part of the paper, we analyse the results of some numerical simulations. Such simulations give a hint on the behaviour of the system in the case where the white noise forcing fails the assumptions of the main theorem The IMA Volumes in Mathematics an its Applications, vol. 14

The Yeast<i>TEL1</i>Gene Partially Substitutes for Human<i>ATM</i>in Suppressing Hyperrecombination, Radiation-Induced Apoptosis and Telomere Shortening in A-T Cells

Homozygous mutations in the human ATM gene lead to a pleiotropic clinical phenotype of ataxia-telangiectasia (A-T) patients and correlating cellular deficiencies in cells derived from A-T donors. Saccharomyces cerevisiae tel1 mutants lacking Tel1p, which is the closest sequence homologue to the ATM protein, share some of the cellular defects with A-T. Through genetic complementation of A-T cells with the yeast TEL1 gene, we provide evidence that Tel1p can partially compensate for ATM in suppressing hyperrecombination, radiation-induced apoptosis, and telomere shortening. Complementation appears to be independent of p53 activation. The data provided suggest that TEL1 is a functional homologue of human ATM in yeast, and they help to elucidate different cellular and biochemical pathways in human cells regulated by the ATM protein.</jats:p