共查询到20条相似文献,搜索用时 125 毫秒
1.
利用分子束外延方法研制出了高质量的InGaAs/AlGaAs庆变量子阱激光器外延材料,其最低的阈值电流密度可达到120A/cm^2,激光波长在980nm左右。获得了高性能的适合于掺铒光纤放大器用的980nm量子阱激光器泵浦源,其典型的阈值电流为15mA,外微分量子效率的典型值和最好值分别为0.8mW/mA和1.0mW/mA,线性输出功率大于120mW,在20℃-50℃的特征温度T0为125K。器件 相似文献
2.
GaAs/GaAlAs低阈值垂直腔面发射激光器 总被引:3,自引:0,他引:3
通过对增益波导型GaAs/GaAlAs垂直腔面发射激光器的材料生长和工艺制作的研究,实现了在室温下的脉冲激射。其激射阈值电流低达10mA,输出光功率不低于0.3mw,有的可达0.7mw以上,器件单横模、单纵模工作,线宽小于4人。 相似文献
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用低压MOVPE方法研制出了波长为655nm与670nm的GaInP-AlGaInP半导体量子阱可见激光器,并已形成一定的批量生产能力。器件的阈值电流典型值为45mA,输出光功率不小于5mW,最高工作温度不低于50℃,预计20℃时寿命接近100,000小时,主要技术指标与目前进口的同类产品水平相当,完全可以满足实用要求。 相似文献
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用两步液相外延法研制出1.48μm大功率GaInAsP/InP激光器,尾纤输出功率大于30mW。用作掺铒光纤放大器的泵浦光源,双向泵浦小信号增益28dB,经较长时间的实际运行,表明器件性能稳定可靠,温度特性好。 相似文献
8.
准连续在功率二维层叠量子阱激光器列阵 总被引:4,自引:1,他引:3
研究了大功率列阵器件的量子阱结构,材料生长,列阵结构,了技术与封装技术,研制了6条层叠GaAs/AlCaAs量子阱激光器列阵,其峰值功率为404W,电-光转换效率高达43.3%。 相似文献
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利用我们研制的常压MOVPE设备对国产TMGa、TMAl、TMIn和TMSb进行了鉴定,为此分别生长了GaAs、AlGaAs、InP、GaSb外延层和GaAs/AlAs、GaSb/InGaSb超晶格和GaAs/AlGaAs量子阱结构。表征材料纯度的77K载流予迁移率分别达到GaAs:μ_n=56600cm ̄2/V·s,Al_(0.25)Ga_(0.75)As:μ_n=5160cm ̄2/V·s,InP:μ_n=65300cm ̄2/V·s,GaSb:μ_p=5076cm ̄2/V·s。由10个周期的GaAs/AlAs超晶格结构组成的可见光区布拉格反射器已观测到很好的反射光谱和双晶X射线回摆曲线上高达±20级的卫星峰。GaAs/Al_(0.35)Ga_(0.65)As量子阱最小阱宽为10,在liK下由量子尺寸效应导致的光致发光峰能量移动为390meV,其线宽为12meV。这些结果表明上述金属有机化合物已达到较高质量。 相似文献
11.
Z.Y. Nuru C.J. Arendse T.F.G. Muller M. Maaza 《Materials Science and Engineering: B》2012,177(14):1194-1199
We report on the microstructure and optical properties of AlxOy–Pt–AlxOy interference-type multilayer films, deposited by electron beam (e-beam) deposition onto corning 1737 glass, silicon (1 1 1) and copper substrates. The structural properties were investigated by Rutherford backscattering spectrometry, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy and atomic force microscopy. The optical properties were extracted from specular reflection/transmission, diffuse reflectance and emissometer measurements. The stratification of the coatings consists of a semi-transparent middle Pt layer sandwiched between two layers of AlxOy. The top and bottom AlxOy layers were non-stoichiometric with no crystalline phases present. The Pt layer is in the fcc crystalline phase with a broad size distribution and spheroidal shape in and between the rims of AlxOy. The surface roughness of the stack was found to be comparable to the inter-particle distance. The optical calculations confirm a high solar absorptance of ∼0.94 and a low thermal emittance of ∼0.06 for the multilayer stack, which is attributed not only to the optimized nature of the multilayer interference stacks, but also to the specific surface morphology and texture of the coatings. These optical characteristics validate the spectral selectivity of the AlxOy–Pt–AlxOy interference-type multilayer stack for use in high temperature solar-thermal applications. 相似文献
12.
Spectrally selective AlxOy/Pt/AlxOy multilayer absorber coatings were deposited onto corning 1737 glass, Si (111) and copper substrates using electron beam (e-beam) vacuum evaporator at room temperature. The employment of ellipsometric measurements and optical simulation was proposed as an effective method to optimize and deposit multilayer solar absorber coatings. The optical constants (n and k) measured using spectroscopic ellipsometry, showed that both AlxOy layers, which used in the coatings, were dielectric in nature and the Pt layer was semi-transparent. The optimized multilayer coatings exhibited high solar absorptance α ∼ 0.94 ± 0.01 and low thermal emittance ? ∼ 0.06 ± 0.01 at 82 °C. The Rutherford backscattering spectroscopy (RBS) data of AlxOy/Pt/AlxOy multilayer absorber indicated the AlxOy layers present in the coating were nearly stoichiometry. The scanning electron microscope analysis (SEM) result indicated that the average diameter and inter-particles distance of Pt grains were statistically about 146 ± 0.17 nm and 6-10 ± 0.2 nm respectively. 相似文献
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K. Racka I. Kuryliszyn M. Arciszewska W. Dobrowolski J.-M. Broto O. Portugall H. Rakoto B. Raquet V. Dugaev E. I. Slynko V. E. Slynko 《Journal of Superconductivity》2003,16(2):289-291
The Anomalous Hall Effect (AHE) was investigated in IV–VI ferromagnetic semimagnetic semiconductors of Sn1–x
Mn
x
Te codoped with either Eu or Er. The analysis of experimental data is as follows. Hall resistivity and magnetization showed that AHE coefficient R
s
depends on temperature and its value decreases with thetemperature increase. We observe that above ferromagnet–paramagnet transition temperature R
s
changes sign. We discuss the possible physical mechanisms responsible for observed temperature dependence of R
s
, particularly change of the sign. 相似文献
15.
Integration of NiSix based fully silicided metal gates with HfO2 high-k gate dielectrics offers promise for further scaling of complementary metal-oxide- semiconductor devices. A combination of high resolution transmission electron microscopy and small probe electron energy loss spectroscopy (EELS) and energy dispersive X-ray analysis has been applied to study interfacial reactions in the undoped gate stack. NiSi was found to be polycrystalline with the grain size decreasing from top to bottom of NiSix film. Ni content varies near the NiSi/HfOx interface whereby both Ni-rich and monosilicide phases were observed. Spatially non-uniform distribution of oxygen along NiSix/HfO2 interface was observed by dark field Scanning Transmission Electron Microscopy and EELS. Interfacial roughness of NiSix/HfOx was found higher than that of poly-Si/HfO2, likely due to compositional non-uniformity of NiSix. No intermixing between Hf, Ni and Si beyond interfacial roughness was observed. 相似文献
16.
In our previous works, we have shown that most existing ceramic superconductors can be considered to be built of superconductor-semiconductor composite and we have estimated the change in phonon spectrum of the intrinsic superconductor unit if a semiconductor unit is attached to it. Moreover, the proximity effect under the size quantization condition has been examined in the superconductor-semiconductor composite. Each of the stated effects by itself could causeT
c
enhancement in general as more semiconductor blocks are added to the system. We extend our study in this paper to analyze the combined actions of phonon spectral change and proximity effect without size quantization condition onT
c
variation in members of the Tl1 series of high-T
c
superconductors. Our results indicate that an optimumT
c
is obtained if the stated effects are included in the idealized unit cells of the superconductors made up of a superconductor-semiconductor array. 相似文献
17.
A high-pressure technique was adopted to obtain perovskite-type . A new perovskite was characterized to have a cubic symmetry with ; Li and Nb ions in the B-site of perovskite lattice may be in a random arrangement. 相似文献
18.
The preparation conditions of the high TC ceramic superconductor Ba(Pb,Bi)O3 is correlated with the superconducting transition. Transition onsets of all materials are similar, but transition widths and transition completeness is strongly dependent on firing temperature. Only materials prepared over a narrow temperature range, resulting in a nearly ideal weight loss, have a complete and narrow transition. 相似文献
19.
S. Nomura J. Kuwata S.J. Jang L.E. Cross R.E. Newnham 《Materials Research Bulletin》1979,14(6):769-774
The electrostriction in crystals has been investigated using a strain gauge method. In the ferroelectric phase below 140 C, the strain vs the electric field shows a hysteresis, which is ascribed to the effect of ferroelectric domains. A quadratic relation holds between the strain x and the electric polarization P as x = QP2 above about 170 C in the paraelectric phase. Values of the electrostrictive Q coefficients are determined from the measurements near 190 C, as Q11 = 1.6·10?2m4/C2, Q12 = ?0.86·10?2m4/C2, and Q44 = 0.85·10?2m4/C2. 相似文献
20.
N. M?ri M. Takai A. Tomioka S. Ogawa Y. Ueda H. Takahashi S. Katano 《Journal of Superconductivity》1994,7(5):819-821
The superconducting transition temperature,T
c
, of La2–x
Ba
x
CuO4 has been measured under high pressure up to 8 GPa.T
c
is found to change drastically at the pressure where the structural phase transition takes place. This finding clearly indicates that there exists an intimate relation between the crystal structure and superconductivity. 相似文献