2,418 research outputs found

    Ultrafast all-optical wavelength conversion in silicon-insulator waveguides by means of cross phase modulation using 300 femtosecond pulses

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    In this paper we report the ultrafast all-optical wavelength conversion in Silicon-on-Insulator (SOI) waveguides. We used a pump-probe setup with 300 femtosecond pulses to demonstrate large temporal phase-shifts, caused by the Kerr effect and free carrier generation. Large wavelength shifts of a 1683nm probe signal have been observed. The wavelength conversion, ranging from 10nm redshifts to 15nm blueshifts, depending on the time delay between the pump and probe pulses, is caused by the pump induced Cross Phase Modulation. Furthermore, an all-optical switching scheme using SOI microring resonators is discussed. These results enable ultrafast all-optical switching using SOI microring resonators

    Nd-complex-doped polymer channel waveguide laser

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    Laser operation at 1060 nm with slope efficiency of 0.95% and 440 μW output power for 2% outcoupling was demonstrated in Nd-complex-doped FDA/epoxy channel waveguides, in what to our knowledge is the first report of a rare-earth-ion-doped polymer waveguide laser. The threshold was 45 mW of absorbed pump power

    Health inequalities and development plans in Iran: An analysis of the past three decades (1984–2010)

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    Introduction: Reducing inequalities in health care is one of the main challenges in all countries. In Iran as in other oil-exporting upper middle income countries, we expected to witness fewer inequalities especially in the health sector with the increase in governmental revenues. Methods: This study presents an inequalities assessment of health care expenditures in Iran. We used data from the Household Income and Expenditure Survey (HIES) in Iran from 1984–2010. The analysis included 308,735 urban and 342,532 rural households. Results: The results suggest heightened inequality in health care expenditures in Iran over the past three decades, including an increase in the gap between urban and rural areas. Furthermore, inflation has affected the poor more than the rich. The Kakwani progressivity index in all years is positive, averaging 0.436 in rural and 0.470 in urban areas during the time period of analysis. Compared to inequality in income distribution over the last 30 years, health expenditures continuously show more inequality and progressivity over the same period of time. Conclusions: According to the result of our study, during this period Iran introduced four National Development Plans (NDPs); however, the NDPs failed to provide sustainable strategies for reducing inequalities in health care expenditures. Policies that protect vulnerable groups should be prioritized

    Ultrafast all-optical wavelength conversion in silicon waveguides using femtosecond pump-probe pulses

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    Experimental results on ultrafast all-optical wavelength conversion in silicon-on-insulator waveguides are presented. Red and blue shifts of 10nm have been observed in femtosecond pump-probe experiments. Alloptical switching and the importance of waveguide dispersion are discussed

    Self Phase Modulation and Stimulated Raman Scattering due to High Power Femtosecond Pulse Propagation in Silicon-on-Insulator Waveguides.

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    Self Phase Modulation (SPM) and Stimulated Raman Scattering (SRS) in silicon waveguides have been observed and will be discussed theoretically using a modified Nonlinear Schrödinger Equation. The high optical peak powers needed for the experiments were obtained by coupling sub-picosecond (200fs) transform limited pulses with a spectral width of 12nm into a single mode silicon waveguide. Spectral broadening up to 50nm has been observed due to Self Phase Modulation. An intensity increase of the idler spectrum around 1650nm at the expense of the 1550nm pump signal has been observed as function of pump power, indicating the presence of Stimulated Raman Scattering

    Intensive Short-Term Dynamic Psychotherapy: A Systematic Review and Meta-analysis of Outcome Research

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    Abstract. Based on over forty years of videotaped case-based research, Habib Da-vanloo of McGill University, Canada, discovered some of the core ingredients that can enable direct and rapid access to the unconscious in resistant3 patients, patients with functional disorders, and patients with fragile character structure. We will describe here some of the main research findings that culminated in his description of a central thera-peutic process involved in the intensive short-term dynamic psychotherapy (ISTDP) model. We will also describe the evolution of the technique over the past thirty years and summarize the empirical base for Davanloo’s ISTDP
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