GaSb-based vertical-cavity surface-emitting lasers with an emission wavelength at 3 μm.

GaSb-based electrically pumped vertical-cavity surface-emitting lasers (VCSELs) with a buried tunnel junction emitting at 3 μm are demonstrated. To achieve this, a low optical loss VCSEL concept with an undoped epitaxial distributed Bragg reflector and intracavity contact is presented. The devices operate up to 5°C continuous wave and up to 50°C in pulsed mode.

On-Chip Generation, Routing, and Detection of Resonance Fluorescence.

Quantum optical circuits can be used to generate, manipulate, and exploit nonclassical states of light to push semiconductor based photonic information technologies to the quantum limit. Here, we report the on-chip generation of quantum light from individual, resonantly excited self-assembled InGaAs quantum dots, efficient routing over length scales ≥1 mm via GaAs ridge waveguides, and in situ detection using evanescently coupled integrated NbN superconducting single photon detectors fabricated on the same chip. By temporally filtering the time-resolved luminescence signal stemming from single quantum dots we use the quantum optical circuit to perform time-resolved excitation spectroscopy on single dots and demonstrate resonance fluorescence with a line-width of 10 ± 1 μeV; key elements needed for the use of single photons in prototypical quantum photonic circuits.

[Dehydrogenases reducing NAD+ in the presence of D (-) 3- phosphoglycerate in mycobacteria (BCG, H37Ra, M. phlei)].

Referring to the elution volume on a Sephadex G-150 column only one specific peak is obtained, the same for the BCG, H37Ra and Mycobacterium phlei strains grown on Sauton synthetic medium. Some properties of these partially purified dehydrogenases are studied (conservation and dialysis in media of different salt concentrations, equilibrium constant, Km, heat stability). All enzyme preparations from tubercle bacilli (BCG, H37Ra) are readily inactivated by heat and are very unstable in solutions of low ionic strength.

[Polyol dehydrogenases in mycobacteria (author's transl)].

Contrary to the the tubercle bacilli (H37Ra, BCG), Mycobacterium phlei, grown on Sauton medium, formed the NAD+ dependent dehydrogenases that catalyse the oxidation of ribitol, sorbitol and mannitol. These enzymes were separated by chromatography on DEAE-cellulose and Sephadex G-200. In the present work we have principally studied the ribitol dehydrogenase.

[Enzymatic differences in mycobacteria. Ribitol dehydrogenase].

Contrary to the tubercle Bacilli (H37Ra, BCG), Mycobacterium phlei has a ribitol-NAD dehydrogenase (that also oxidizes, although to a lesser extent, erythritol and glycerol). This difference is observed with the Bacteria grown on Sauton's medium, as well as after their adaptation to ribitol. The extracts of all these Mycobacteria reduce, NADP in the presence of glycerol, ribitol or erythritol, though very slowly.

[Asparagine metabolism in mycobacteria. II. -- Asparagine hydrolysis and aspartohydroxamic acid formation and hydrolysis catalysed by M. fortuitum, M. phlei and BCG asparaginases (author's transl)].

Crude extracts of BCG, M. fortuitum and M. phlei, hydrolyse asparagine (I) and L-beta-asparthohydroxamic acid (III), and catalyse the synthesis of aspartohydroxamic acid from asparagine and hydroxylamine (II).