988 resultados para NETTRA-G2-FIFO.


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A 1.55μm Fabry-Perot (F-P) thermo-optical tunable filter is fabricated. The cavity is made of amorphous silicon (a-Si) layer grown by electron-beam evaporation technique. Due to the excellent thermo-optical property of a-Si, the refractive index of the F-P cavity will be changed by heating; the transmittance resonant peak will therefore shift substantially. The measured tuning range is 12nm, FWHM (full-width-at-half-maximum) of the transmission peak is 9nm, and heating efficiency is 0.1K/mW. The large FWHM is mainly due to the non-ideal coating deposition and mirror undulation. Possible improvements to increase the efficiency of heating are suggested.

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研究了基于SOI(silicon-on-insulator)材料的阵列波导光栅(AWG)分波器件,给出了此器件材料色散的数值拟合公式,进而利用BPM方法研究了材料色散脊型波导结构变化和器件制做中刻蚀深度误差对波导有效折射率和波分复用模块性能的影响。结果表明,刻蚀深度误差对模块性能优劣起关键作用。

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提出了一种提高多量子阱电吸收调制DFB-LD集成器件(EML)耦合效率的对接生长方法。采用LP-MOCVD外延方法,制作了对接方法不同的三种样片,通过扫描电镜研究它们的表面及对接界面形貌,发现新对接结构的样片具有更好的对接界面。制作出相应的三种EML管芯,从测量所得到的出光功率特性曲线,计算出不同对接方法下EML管芯的耦合效率和外量子效率。实验结果表明,这种对接生长方案,可以获得光滑的对界面,显著提高了激光器和调制器之间的耦合效率(从常规的17%提高到78%)及EML器件的外量子效率(从0.03mW/mA提高到0.15mW/mA)。

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用近空间华法在CdS薄膜上沉积了CdTe薄膜。研究了在两种保护气氛下所沉积的多晶CdTe薄膜在后处理后的微结构、表面形貌及光致发光(PL)谱,并研究了CdTe表面的CdS/CdTe界面的P谱的区别,根据薄膜的微结构对碲化镉在太阳电池中的应用进行了讨论。

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A fitting process is used to measure the cavity loss and the quasi-Fermi-level separation for Fabry- Perot semiconductor lasers. From the amplified spontaneous emission (ASE) spectrum, the gain spectrum and single-pass ASE obtained by the Cassidy method are applied in the fitting process. For a 1550nm quantum well InGaAsP ridge waveguide laser, the cavity loss of about ~24cm~(-1) is obtained.

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作为大规模集成电路和化合物半导体光电子器件的制造技术共同构成的一门高新技术,硅基光电子技术越来越受到重视。文章着重介绍中国科学院半导体研究所外延生长SiGe/Si量子结构和Si基器件研究的结果

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Si基光电子集成(OEIC)光接收机在光通信系统接入网、光互连、光存储等方面有着广泛的应用前景。本文综述Si基OEIC光接收芯片的研究现状,分析了其发展趋势,探讨了进一步提高性能的途径。

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本文分析了校准方程的关系,提出对于互易的测试夹具,使用一个传输标准得到的四个线性方程可以用同时用于校准计算。在这个关系的基础上,讨论了TSM(thru-short-match)和TRL(thru-reflect-line)方法中的方程选择。实验和分析表明不同的选择会导致不同精度的结果,校准精度可以通过利用已建立的关系和合适地选择方程得以提高。已建立的理论也可应用于TOM和LRL方法。

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用射频等离子体辅助分子束外延技术(RF-MBE)在c面蓝宝石衬底上外延了高质量的GaN膜以及AlN/GaN超晶格结构极化感应二维电子气材料。所获得的掺Si的GaN膜室温电子浓度为2.2 * 10~(18)cm~(-3),相应的电子迁移率为221cm~2/(V·s);1μm厚的GaN外延膜的(0002)X射线衍射摇摆曲线半高宽(FWHM)为7’;极化感应产生的二维电子气室温电子迁移率达到1086cm~2/(V·s),相应的二维电子气面密度为7.5 * 10~(12)cm~(-2)。

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Highly oriented voids-free 3C-SiC heteroepitaxial layers are grown on φ50mm Si (100) substrates by low pressure chemical vapor deposition (LPCVD). The initial stage of carbonization and the surface morphology of carbonization layers of Si(100) are studied using reflection high energy electron diffraction (RHEED) and scanning electron microscopy (SEM). It is shown that the optimized carbonization temperature for the growth of voids-free 3S-SiC on Si (100) substrates is 1100 ℃. The electrical properties of SiC layers are characterized using Van der Pauw method. The I-V, C-V, and the temperature dependence of I-V characteristics in n-3C-SiC-p-Si heterojunctions with AuGeNi and Al electrical pads are investigated. It is shown that the maximum reverse breakdown voltage of the n-3C-SiC-p-Si heterojunction diodes reaches to 220V at room temperature. These results indicate that the SiC/Si heterojunction diode can be used to fabricate the wide bandgap emitter SiC/Si heterojunction bipolar transistors (HBT's).

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The Raman measurements have been performed with the back-scattering geometry on the SiC films grown on Si(100) and sapphire (0001) by LPCVD. Typical TO and LO phonon peaks of 3C-SiC were observed for all the samples grown on Si and apphire substrates, indicating the epilayers are 3C-SiC polytype. Using a free-standing 3C-SiC film removed from Si(100) as a free-stress sample, the stresses of 3C-SiC on Si(100) and sapphire (0001) were estimated according to the shift of TO and LO phonons.

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降低InGaN的维数是提高GaN基发光器件发光效率的一种非常有效的方法,本文的工作主要集中在高密度InGaN量子点的生长和分析上。在MOCVD设备上,经过钝化和低温两个特殊工艺条件,在高温GaN表面生长了一层低温岛状GaN,形成表面形貌的起伏,进而导致表面应力的不均匀分布。在这一层低温岛状GaN的诱导性作用下生长并形成InGaN量子点。通过原子力显微镜、透射电子显微镜和光致发光谱对其微观形貌和光学性质进行了观察和研究。从原子力显微镜以及透射电子显微镜观察得到的结果表明

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密集波分复用(DWDM)已经成为光纤通信的主要发展方向,光上下路分插复用器(OADM)作为WDM网络中的关键技术,它的优劣将直接影响通信网络的性能。侧重于从器件的角度对OADM的功能和发展现状进行介绍,并对其构成的关键器件的发展进行了概述。

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应用深能级瞬态谱(DLTS)技术研究分子束外延(MBE)生长的high electron mobility transistors (HEMT)和Pseudomorphic high electron mobility transistors (P-HEMT)结构深中心行为。样品的DLTS谱表明,在HEMT和P-HEMT结构的n-AlGaAs层里存在着较大浓度(10~(15)-10~(17)cm~(-3))和俘获截面(10~(-16)cm~2)的近禁带中部电子争阱。它们可能与AlGaAs层的氧含量有关。同时还观察到P-HEMT结构晶格不匹配的AlGaAs/InGaAs/GaAs系统在AlGaAs里产生的应力引起DX中心(与硅有关)能级位置的有序移动。其移动量可作为应力大小的一个判据,表明DLTS技术是定性识别此应力的可靠和简便的工具。

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研究分子束外延(MBE)生长的应变In_(0.2)Ga_(0.8)As/GaAs折射率梯度变化异质结单量子阱激光二极管的快速热处理(RTA)效应。结果表明,RTA移除了InCaAs/GaAs界面非辐射中心,提高77K光致发光效率和有源层电子发射。同时Al和Ga原子互扩散,也增加了AlGaAs波导层DX中心浓度。RTA处理后样品电流冲击老化实验证明DX中心浓度呈现出相应的增加。这表明DX中心可能是激光二极管性能退化的原因之一。