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991.
A. Nishiyama G. ter Horst P. M. Zagwijn G. N. van den Hoven J. W. M. Frenken F. Garten A. R. Schlatmann J. Vrijmoeth 《Surface science》1996,350(1-3):229-238
A growth mode and interface structure analysis has been performed for Ag deposited at a high temperature of 300°C on the HF-treated Si(111):H surface by means of medium-energy ion scattering and elastic recoil detection analysis of hydrogen. The measurements show that Ag grows in the Volmer-Weber mode and that the Ag islands on the surface are epitaxial with respect to the substrate. The preferential azimuthal orientation is A-type only when Ag is deposited slowly. The interface does not reconstruct to the √3 × √3-Ag structure, which is normally observed for Ag deposition above 200°C on the Si(111)7 × 7 surface, but retain bulk-like structure. The presence of hydrogen at the interface is demonstrated after deposition of thick (1100 Å) Ag films. However, the amount of hydrogen at the interface is not a full monolayer. This partial desorption of hydrogen from the interface explains why the Schottky barrier heights of Ag/Si(111):H diodes are close to those of Ag/Si(111)7 × 7 and Ag/Si(111)2 × 1. 相似文献
992.
Based on a set of microoptics the output radiation from a continuous wave (CW) linear laser diode array is coupled into a multi-mode optical fiber of 400 μm diameter.The CW linear laser diode array is a 1 cm laser diode bar with 19 stripes with 100 μm aperture spaced on 500 μm centers.The coupling system contains packaged laser diode bar,fast axis collimator,slow axis collimation array,beam transformation system and focusing system.The high brightness,high power density and single fiber output of a laser diode bar is achieved.The coupling efficiency is 65% and the power density is up to 1.03×104 W/cm2. 相似文献
993.
994.
I. I. Eru 《International Journal of Infrared and Millimeter Waves》1994,15(7):1315-1323
Quasioptical 2-mm and 1,5 mixer receivers for room temperature operation are described. Receivers incorporates polarization-rotationing dual-beam interferometers, used as antenna-heterodyn diplexer, waveguide Schottky diode mixers, carcinotron (BWO) and carcinitron with the frequency doubler, used as local oscillators (LO), and GaAs IF amplifiers. The best receiver noise temperatures are 600K (DSB) at 2,0-mm and 800K (DSB) at 1,5-mm wavelengths bands. The performance of these receivers is also discussed. 相似文献
995.
V. I. Piddiachii S. A. Peskovatskii 《International Journal of Infrared and Millimeter Waves》2003,24(1):43-54
The RF matching problem in the input circuit of the mm-wavelength whisker contacted Schottky diode mixer is studied. The experimental results, obtained on the 3mm wavelength mixer mounts in the broad band of frequencies from 80 to 115 GHz are presented. It is shown that advantage in the receiver noise temperature may be realized by the use of a full-height instead of 1/4-reduced-height waveguide because of reduction loss in the mixer input circuit even beginning from the 3mm-wavelength. With a full-height waveguide mixer the double sideband (DSB) receiver noise temperature is 300 divided by 350K over the 85 to 110 GHz band. Input bandwidth of the fullheight waveguide mixer (cap delta f
S/f
SO greater than 30%) is equal to 1/2-and close to 1/4-reduced-height waveguide mixers. 相似文献
996.
997.
本文测量了GaP纯绿发光二极管在室温和液氮温度下的近红外发光光谱,观测到许多重叠的宽带发光.按高斯线型对光谱进行拟合,将其分解为6个发光谱峰,讨论了这些深能级发光的来源和它们对GaP发光二极管的发光强度的影响. 相似文献
998.
1.3μmDFB半导体激光超短脉冲的产生及其压缩 总被引:2,自引:1,他引:1
本文首次报道1.3μm单模超短脉冲产生及压缩实验。通过梳状波电脉冲直接调制DCPBH-DFB半导体激光器,获得22ps单模光滑脉冲;然后利用G-T干涉仪压缩得到近变换极限超短脉冲。脉宽为9.3ps,峰值功率超过200mW,重复频率1GHz,时间带宽乘积为0.39,脉冲压缩比为2.4。最后对实验结果进行了讨论。 相似文献
999.
激光二极管端面泵浦的单频固体激光器的理论研究 总被引:1,自引:0,他引:1
给出了激光二极管端面泵浦的驻波激光器单频运转时的最大泵浦功率与腔参数和激光介质参烽之间的简单函数关系,对于单频激光器的设计具有实际指导意义。 相似文献
1000.