Nanosecond gating of superconducting nanowire single-photon detectors using cryogenic bias circuitry.

Superconducting nanowire single-photon detectors (SNSPDs) show near unity efficiency, low dark count rate, and short recovery time. Combining these characteristics with temporal control of SNSPDs broadens their applications as in active de-latching for higher dynamic range counting or temporal filtering for pump-probe spectroscopy or LiDAR. To that end, we demonstrate active gating of an SNSPD with a minimum off-to-on rise time of 2.

Nonlinear down-conversion in a single quantum dot.

Tailored nanoscale quantum light sources, matching the specific needs of use cases, are crucial building blocks for photonic quantum technologies. Several different approaches to realize solid-state quantum emitters with high performance have been pursued and different concepts for energy tuning have been established. However, the properties of the emitted photons are always defined by the individual quantum emitter and can therefore not be controlled with full flexibility.

Electric-field-induced second harmonic generation in silicon dioxide.

Electric-field-induced second harmonic generation (EFISH) as a third order nonlinear process is of high practical interest for the realization of functional nonlinear structures. EFISH in materials with vanishing χ and non-zero χ offers huge potential, e.g.

Impact of carbon-ion implantation on the nonlinear optical susceptibility of LiNbO.

In this work we study the impact of ion implantation on the nonlinear optical properties in MgO:LiNbO via confocal second-harmonic microscopy. In detail, we spatially characterize the nonlinear susceptibility in carbon-ion implanted lithium niobate planar waveguides for different implantation energies and fluences, as well as the effect of annealing. In a further step, a computational simulation is used to calculate the implantation range of carbon-ions and the corresponding defect density distribution.

Vibrational properties of the LiNbO3 z-surfaces.

The existence of localized vibrational modes both at the positive and at the negative LiNbO3 (0001) surface is demonstrated by means of first-principles calculations and Raman spectroscopy measurements. First, the phonon modes of the crystal bulk and of the (0001) surface are calculated within the density functional theory. In a second step, the Raman spectra of LiNbO(3) bulk and of the two surfaces are measured.

Universal antenatal screening for syphilis: is it still justified economically? A 10-year retrospective analysis.

Objective: Because universal prenatal screening for syphilis has recently been called into question, we documented the development of syphilis in Austria and analysed the effectiveness of current antenatal syphilis screening practices.

Methods: The development of syphilis in Austria and Vienna was determined based on the data published by the Austrian Bureau of National Statistics (Statistik Austria) and the Vienna Health Authority (Gesundheitsamt Wien, MA15), respectively. The data obtained for Vienna were then compared with those for the remaining eight federal provinces.

Placental passage of clarithromycin surpasses other macrolide antibiotics.

Objective: Infection of the amnion cavity with Ureaplasma urealyticum continues to be a therapeutic challenge. The transplacental transfer rates of macrolide antibiotics are low, and tetracyclines and quinolones are contraindicated in pregnancy. The aim of this study was to investigate placental transfer of clarithromycin in a well-studied placental perfusion model to determine whether clarithromycin surpasses the transfer rate of other macrolide antibiotics in similar models.

Continuous microspinal anaesthesia: another perspective on mechanisms inducing cauda equina syndrome.

Continuous spinal anaesthesia through a microspinal catheter technique has been criticised on several grounds and is now rarely used. This paper reviews the possible causes of the cauda equina syndrome which have been described and, on the basis of research in cadaver preparations, a glass 'spine' model and clinical experience in over 200 cases, suggests how these problems might be avoided. The use of careful insertion techniques, limiting the length of catheter inserted into the subarachnoid space and the use of no stronger than 0.