2,872 research outputs found

    Strategy for Integrated Water Supply, Wastewater Treatment and Disposal Systems for Small Communes in Poland Case study - Master and Action Plans (MaAP) for the Bystra River Catchment

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    This report is the final report of the project: "Strategy for integrated Water Supply, Wastewater Treatment and Disposal System for Small Communes in Poland: Case study - Master and Action Plans (MaAP) for the Bystra river catchment". The project is part of the Programme of Bilateral Co-operation between the Norwegian Ministry of Environment and the Ministry of Environmental Protection, Natural Resources and Forestry in Poland. It has been implemented by the Norwegian Institute for Water Research (NIVA) and has been funded by the Norwegian Pollution Control Authority (SFT). The Institute of Environmental Protection (IOS) in Poland has been responsible for the co-ordination in Poland, sponsored by the National Foundation for Environmental Protection and Water Management. The project provides an input to the process of wastewater master planning methodology in Poland, presented as a case study for the Bystra river catchment, and based on Norwegian procedures. on Norwegian procedures. This report presents the main objectives, activities and conclusions of the project, as well as a short presentation of Norwegian experiences relevant to the project. Five report have been elaborated prior to this report, where the entire project development is described

    Nanobeam photonic crystal cavity quantum dot laser

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    The lasing behavior of one dimensional GaAs nanobeam cavities with embedded InAs quantum dots is studied at room temperature. Lasing is observed throughout the quantum dot PL spectrum, and the wavelength dependence of the threshold is calculated. We study the cavity lasers under both 780 nm and 980 nm pump, finding thresholds as low as 0.3 uW and 19 uW for the two pump wavelengths, respectively. Finally, the nanobeam cavity laser wavelengths are tuned by up to 7 nm by employing a fiber taper in near proximity to the cavities. The fiber taper is used both to efficiently pump the cavity and collect the cavity emission.Comment: 8 pages; 6 figure

    Transient chirp in high speed photonic crystal quantum dots lasers with controlled spontaneous emission

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    We report on a series of experiments on the dynamics of spontaneous emission controlled nanolasers. The laser cavity is a photonic crystal slab cavity, embedding self-assembled quantum dots as gain material. The implementation of cavity electrodynamics effects increases significantly the large signal modulation bandwidth, with measured modulation speeds of the order of 10 GHz while keeping an extinction ratio of 19 dB. A linear transient wavelength shift is reported, corresponding to a chirp of less than 100 pm for a 35-ps laser pulse. We observe that the chirp characteristics are independent of the repetition rate of the laser up to 10 GHz

    Theory of Pump Depletion and Spike Formation in Stimulated Raman Scattering

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    By using the inverse spectral transform, the SRS equations are solved and the explicit output data is given for arbitrary laser pump and Stokes seed profiles injected on a vacuum of optical phonons. For long duration laser pulses, this solution is modified such as to take into account the damping rate of the optical phonon wave. This model is used to interprete the experiments of Druhl, Wenzel and Carlsten (Phys. Rev. Lett., (1983) vol. 51, p. 1171), in particular the creation of a spike of (anomalous) pump radiation. The related nonlinear Fourier spectrum does not contain discrete eigenvalue, hence this Raman spike is not a soliton.Comment: LaTex file, includes two figures in LaTex format, 9 page

    Limitations of two-level emitters as nonlinearities in two-photon controlled-phase gates

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    We investigate the origin of imperfections in the fidelity of a two-photon controlled-phase gate based on two-level-emitter non-linearities. We focus on a passive system that operates without external modulations to enhance its performance. We demonstrate that the fidelity of the gate is limited by opposing requirements on the input pulse width for one- and two-photon scattering events. For one-photon scattering, the spectral pulse width must be narrow compared to the emitter linewidth, while two-photon scattering processes require the pulse width and emitter linewidth to be comparable. We find that these opposing requirements limit the maximum fidelity of the two-photon controlled-phase gate for Gaussian photon pulses to 84%.Comment: 7 pages, 6 figure

    A bright nanowire single photon source based on SiV centers in diamond

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    The practical implementation of many quantum technologies relies on the development of robust and bright single photon sources that operate at room temperature. The negatively charged silicon-vacancy (SiV-) color center in diamond is a possible candidate for such a single photon source. However, due to the high refraction index mismatch to air, color centers in diamond typically exhibit low photon out-coupling. An additional shortcoming is due to the random localization of native defects in the diamond sample. Here we demonstrate deterministic implantation of Si ions with high conversion efficiency to single SiV- centers, targeted to fabricated nanowires. The co-localization of single SiV- centers with the nanostructures yields a ten times higher light coupling efficiency than for single SiV- centers in bulk diamond. This enhanced photon out-coupling, together with the intrinsic scalability of the SiV- creation method, enables a new class of devices for integrated photonics and quantum science.Comment: 15 pages, 5 figure

    Scalable Focused Ion Beam Creation of Nearly Lifetime-Limited Single Quantum Emitters in Diamond Nanostructures

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    The controlled creation of defect center---nanocavity systems is one of the outstanding challenges for efficiently interfacing spin quantum memories with photons for photon-based entanglement operations in a quantum network. Here, we demonstrate direct, maskless creation of atom-like single silicon-vacancy (SiV) centers in diamond nanostructures via focused ion beam implantation with 32\sim 32 nm lateral precision and <50< 50 nm positioning accuracy relative to a nanocavity. Moreover, we determine the Si+ ion to SiV center conversion yield to 2.5%\sim 2.5\% and observe a 10-fold conversion yield increase by additional electron irradiation. We extract inhomogeneously broadened ensemble emission linewidths of 51\sim 51 GHz, and close to lifetime-limited single-emitter transition linewidths down to 126±13126 \pm13 MHz corresponding to 1.4\sim 1.4-times the natural linewidth. This demonstration of deterministic creation of optically coherent solid-state single quantum systems is an important step towards development of scalable quantum optical devices

    The Effects of Pregnenolone 16α-Carbonitrile Dosing on Digoxin Pharmacokinetics and Intestinal Absorption in the Rat

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    The effect of Pgp induction in rats by pregnenolone 16α-carbonitrile (PCN) (3 days, 35 mg/kg/d, p.o.) on digoxin pharmacokinetics and intestinal transport has been assessed. After intravenous or oral digoxin dosing the arterial and hepatic portal vein (oral) AUC(0-24h) were significantly reduced by PCN pre-treatment. Biliary digoxin clearance increased 2-fold following PCN treatment. PCN significantly increased net digoxin secretion (2.05- and 4.5-fold respectively) in ileum and colon but not in duodenum or jejunum. This increased secretion correlated with increased Pgp protein expression in ileum and colon. Both intestinal and biliary excretion therefore contribute to altered digoxin disposition following PCN

    Integral Multiphase Turbulence Compressible Jet Expansion Model for Accidental Releases from Pressurized Containments

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    The accurate prediction of the conditions of a pressurized jet upon its expansion to atmospheric pressure is of fundamental importance in assessing the consequences associated with accidental releases of hazardous fluids from pressurized containments. An integral multiphase compressible jet expansion model which for the first time accounts for turbulence generation is presented. Real fluid behavior is accounted for applying a suitable equation of state. By use of the accidental release of two-phase CO2 from a pressurized system as an example, the proposed model is shown to provide far better predictions of the fully expanded jet momentum and hence its downstream flow characteristics as compared to existing integral models where the impact of turbulence generation is ignored
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