230 research outputs found

    Narrow-Linewidth Distributed Feedback Channel Waveguide Laser in Al2_2O3_3:Er3+^{3+}

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    We report on the fabrication and characterization of a distributed feedback channel waveguide laser in erbium-doped aluminium oxide on a standard thermally oxidized silicon substrate. Holographically-written surface-relief Bragg gratings have been integrated with the aluminium oxide waveguides via reactive ion etching of a silicon dioxide overlay film. The laser operates at a wavelength of 1545.2 nm and exhibits a threshold of 2.2 mW absorbed pump power, while it produces a maximum output power of 3 mW. The emission is TE polarized and has a Lorentzian linewidth of 1.70±0.58 kHz, which corresponds to a Q-factor of 1.14×E11

    High-Q distributed-Bragg-grating laser cavities

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    Applying Bragg gratings in Al2O3 channel waveguides, we demonstrate distributed Bragg reflectors with Q-factors of 1.02x10e6. An integrated Al2O3:Yb3+ waveguide laser with 67% slope efficiency and 47 mW output power is achieved with such cavities

    Ultra-high, broadband gain in a lattice-engineered, Yb-doped double tungstate channel waveguide

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    150 dB/cm gain over 55 nm wavelength range between 977-1032 nm is obtained in a 47.5% Yb-doped potassium double tungstate waveguide amplifier. The dependence of luminescence lifetime and gain on Yb concentration is investigated

    Single-Frequency, Narrow-Linewidth Distributed Feedback Waveguide Laser in Al2O3:Er3+ on Silicon

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    A distributed feedback channel waveguide laser in erbium-doped aluminum oxide on a silicon substrate is reported. The optically pumped laser has a threshold pump power of 15 mW and emits 3 mW in single-frequency operation at 1545.2 nm wavelength with a slope efficiency of 6.2% and linewidth of 15 kHz

    On-chip integrated amplifiers and lasers utilizing rare-earth-ion activation

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    This contribution reviews our recent results on rare-earth-ion-doped integrated amplifiers and lasers. We have concentrated our efforts on complex-doped polymers, amorphous Al2O3, and crystalline potassium double tungstates

    Heterogeneity of the pharmacologic treatment of allergic rhinitis in Europe based on MIDAS and OTCims platforms

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    Rinitis al·lèrgica; Costos; MedicamentsRinitis alérgica; Costos; MedicamentosAllergic rhinitis; Costs; MedicationsBackground The practice of allergology varies widely between countries, and the costs and sales for the treatment of rhinitis differ depending on practices and health systems. To understand these differences and their implications, the rhinitis market was studied in some of the EU countries. Methods We conducted a pharmaco-epidemiological database analysis to assess the medications that were being prescribed for allergic rhinitis in the years 2016, 2017 and 2018. We used the IQVIA platforms for prescribed medicines (MIDAS®—Meaningful Integration of Data, Analytics and Services) and for OTC medicines (OTC International Market Tracking—OTCims). We selected the five most important markets in the EU (France, Germany, Italy, Poland and Spain). Results Intranasal decongestants were excluded from the analyses because they are rarely prescribed for allergic rhinitis. For both Standard Units (SU) and costs, France is leading the other countries. In terms of SU, the four other countries are similar. For costs, Poland is lower than the three others. However, medication use differs largely. For 2018, in SU, intranasal corticosteroid is the first treatment in Poland (70.0%), France (51.3%), Spain (51.1%) and Germany (50.3%), whereas the Italian market is dominated by systemic antihistamines (41.4%) followed by intranasal corticosteroids (30.1%). Results of other years were similar. Discussion There are major differences between countries in terms of rhinoconjunctivitis medication usage

    Integrated Al2O3:Er3+ microring and distributed feedback lasers on silicon

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    Integrated rare-earth-ion-doped dielectric lasers have found\ud numerous applications in the medical, scientific, military and industrial fields, thanks to their high stability, low noise, narrow linewidth emission and broad wavelength tunability. Its favorable optical properties and compatibility with existing silicon waveguide technology make rare-earth-ion-doped aluminum oxide (Al2O3) a very promising gain medium to realize such integrated lasers.\ud Al2O3:Er3+ waveguide lasers are of interest due to their emission near 1.55 μm in the telecommunication C-band. The fabrication of low-loss Al2O3:Er3+ waveguides and internal optical gain over an 80-nm wavelength range with a peak gain of 2.0 dB/cm enabled the realization of various integrated Al2O3:Er3+ lasers on standard thermally oxidized silicon substrates. We report on the fabrication and performance of optically pumped channel waveguide ring and distributed feedback (DFB) lasers in Al2O3:Er3+. The low threshold ring-cavity lasers provide laser wavelength selection in the range 1530–1557 nm when varying the length of the output coupler from the ring. The DFB lasers exhibit output powers of more than 3 mW with slope efficiencies as high as 6.2% in single-frequency operation at 1545.2 nm with\ud linewidths below 15 kHz. These performance data illustrate the significance of Al2O3:Er3+ as a laser gain medium in dense wavelength division multiplexing in telecommunication networks

    Quasi-static crushing response of square hybrid carbon/aramid tube for automotive crash box application

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    One of the essential automotive parts is a crash box, which is essential for initial kinetic energy absorption. However, both vehicle weight and energy-absorbing performance of crash box requirements have to achieve. Recently, crash boxes made of hybrid materials have increasingly studied regarding their better crash performance and weight reduction effects compared to conventional metallic materials. Therefore, the aim of this study is to fabricate a hybrid carbon/aramid composite crash box with a hollow structure and to determine its mechanical properties under quasi-static axial compressive and tensile loading. This study shows that square hybrid carbon/aramid tubes provide an average 57.94 J energy absorption, average 0.72 kJ/kg specific energy absorption, average 62.46 kN crushing peak load, average 748.40 MPa compressive modulus and average 36.29 MPa maximum stress under quasi-static compressive loading. It is suggested that a square hybrid carbon/aramid tube could have the promising potential to replace aluminium or metallic structure to use as an automotive crash box for lightweight applications

    Commentaries on Viewpoint: The ongoing need for good physiological investigation: Obstructive sleep apnea in HIV patients as a paradigm

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    The final publication is available via http://dx.doi.org/10.1152/japplphysiol.00989.2014[Abstract] The intriguing paradigm put forth by Darquenne et al. (3) highlighted that improved therapy against human immunodeficiency virus (HIV) has come at the cost of elevated rates of chronic diseases, such as obstructive sleep apnea (OSA) and obesity, during the highly active antiretroviral therapy (HAART) era.Ministerio de Economía y Competitividad; TIN2013-40686-P
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