989 resultados para 162-980


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We report on the material growth and fabrication of high-performance 980-nm strained quantum-well lasers employing a hybrid material system consisting of an Al-free InGaAs-InGaAsP active region and AlGaAs cladding layers. The use of AlGaAs cladding instead of InGaP provides potential advantages in flexibility of laser design, simple epitaxial growth, and improvement of surface morphology and laser performance. The as-grown InGaAs-InGaAsP(1.6 eV)-AlGaAs(1.95 eV) lasers achieve a low threshold current density of 150 A/cm(2) (at a cavity length of 1500 mu m), internal quantum efficiency of similar to 95%, and low internal loss of 1.8 cm(-1). Both broad-area and ridge-waveguide laser devices are fabricated. For 100-mu m-wide stripe lasers with a cavity length of 800 Irm, a slope efficiency of 1.05 W/A and a characteristic temperature coefficient (T-0) of 230 K are achieved. The lifetime test demonstrates a reliable performance. The comparison with our fabricated InGaAs-InGaAsP(1.6 eV)-AlGaAs(1.87 eV) lasers and Al-free InGaAs-InGaAsP (1.6 eV)-InGaP lasers are also given and discussed. The selective etching between AlGaAs and InGaAsP is successfully used for the formation of a ridge-waveguide structure. For 4-mu m-wide ridge-waveguide laser devices, a maximum output power of 350 mW is achieved. The fundamental mode output power can be up to 190 mW with a slope efficiency as high as 0.94 W/A.

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We present a new generation 980 nm submarine pump module that consists of a hermitically sealed 8-pin ceramic MiniDIL package without thermo-electric cooler.

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本文介绍了提高980 nm半导体激光器可靠性的几种方案,并做了综合评述。进一步介绍了离子辅助镀膜技术在提高980 nm激光器可靠性方面的应用。

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介绍了电子回旋共振等离子体化学气相沉积(简称ECR plasma CVD)法淀积980nm大功率半导体激光器两端面光学膜的工艺条件,探索了膜系监控的方法和优越性,讨论了这种淀积方法的优点和淀积的光学膜的优良特性。

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于2010-11-23批量导入

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于2010-11-23批量导入

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利用分子束外延技术研制出了高质量InGaAs/GaAs应变量子阱材料及量子阱激光器。在室温和10 K温度下,应变量子阱材料的光荧光峰值半宽分别为32 meV和.4 meV,宽接触激光器的阈值电流密度低达140 A/cm~2。脊形波导窄条形量子阱激光器的阈值电流和微分量子效率分别为15 mA和0.8 W/A,线性输出功率大于120 mW,基横模输出功率可达100 mW。InGaAs应变量子阱激光器和单模光纤进行了耦合其组合件出纤光功率典型值为40 mW,最大值可达60 mW,显示出了高的基横模输出功率和高的耦合效率。其组合件在40 mW下,中心发射波长在977 nm,成功地研制出适于掺铒光纤放大器用的应变量子阱激光器泵浦源。

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In this paper, we reported on the fabrication of 980 nm InGaAs/InGaAsP strained quantum-well (QW) lasers with broad waveguide. The laser structure was grown by low-pressure metalorganic chemical vapor deposition on a n(+)- GaAs substrate. For 3 mu m stripe ridge waveguide lasers, the threshold current is 30 mA and the maximum output power and the output power operating in fundamental mode are 350 mW and 200 mW, respectively. The output power from the single mode fiber is up to 100 mW, the coupling efficiency is 50%. We also fabricated 100 mu m broad stripe coated lasers with cavity length of 800 mu m, a threshold current density of 170 A/cm(2), a high slope efficiency of 1.03 W/A and a far-field pattern of 40 x 6 degrees are obtained. The maximum output power of 3.5 W is also obtained for 100 mu m wide coated lasers. (C) 2000 Elsevier Science B.V. All rights reserved.

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Lu2O3:Yb3+/Er3+/Tm3+ nanocrystals have been successfully synthesized by a solvothermal process followed by a subsequent heat treatment at 800 degrees C. Powder X-ray diffraction, transmission electron microscopy, upconversion photoluminescence spectra, and kinetic decay were used to characterize the samples. Under single-wavelength diode laser excitation of 980 nm, the bright blue emissions of Lu2O3:Yb3+, Tm3+ nanocrystals near 477 and 490 nm were observed due to the (1)G(4)-> H-3(6) transition of Tm3+. The bright green UC emissions of Lu2O3:Er3+ nanocrystals appeared near 540 and 565 nm were observed and assigned to the H-2(11/2)-> I-4(15/2) and S-4(3/2)-> I-4(15/2) transitions, respectively, of Er3+. The ratio of the intensity of green luminescence to that of red luminescence decreases with an increase of concentration of Yb3+ in Lu2O3:Er3+ nanocrystals.

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116 hojas : ilustraciones, fotográficas a color.

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Saisi avec 6 autres mss en janvier 1797 dans la bibliothèque de l'abbaye bénédictine de San Benedetto in Polirone près de Mantoue, cf. cote du XVIIIe s. "MS n° 49" (f. de garde); Laffitte, Bulletin du Bibliophile, 1989/2, 300; Delisle, Cab. des mss., II, 414; — ex-libris du XVe s. "Iste liber est mei mag. Johannis Martini de Ferariis de Parma artium ac medicine doctoris" (292v)

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Por el cual se adopta el Reglamento Académico de los Programas de Posgrado del Colegio Mayor de Nuestra Señora del Rosario.

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Teniendo en cuenta tres casos dentro del contexto del conflicto armado donde la jurisdicción penal colombiana estudia la admisión o exclusión de medios probatorios producidos a partir de injerencias de comunicaciones, encontramos que no siempre se aplica la regla de exclusión cuando no cuentan con una orden judicial previa. Ante este problema, buscamos como se ha solucionado, teniendo como referente la el Derecho Internacional Humanitario, el Derecho Internacional de los Derechos Humanos. Lo anterior nos da base para entender la regla de exclusión de que se ha venido desarrollando dentro del Derecho Internacional Penal. Si bien estas reglas nos sirven para solucionar estos tres casos, terminan siendo contradictorios a lo que ha venido desarrollando la Corte Constitucional. De esta manera, si bien esta Corte consideró que la regla de Estatuto de Roma, va en concordancia con la nuestra regla de exclusión nacional, tal afirmación es errónea.