10Gbit/s甚短距离传输系统接收模块研究

本文研究了符合OIF—VSR4—01．0规范的甚短距离（VSR）并行光传输系统转换器集成电路，实现了接收部分转换器集成电路中帧同步、8B／10B解码、12路通道去斜移、检错纠错等模块的设计。在Altera的Stratix GX系列的FPGA上实现了接收部分转换器集成电路。仿真分析的结果表明所设计的各个模块能正确的实现接收部分转换器集成电路的功能，给出了仿真结果。     

Advances and prospects in visible light communications

Visible light communication (VLC) is an emerging technology in optical wireless communication (OWC) that has attracted worldwide research in recent years. VLC can combine communication and illumination together, which could be applied in many application scenarios such as visible light communication local area networks (VLANs), indoor localization, and intelligent lighting. In recent years, pioneering and significant work have been made in the field of VLC. In this paper, an overview of the recent progress in VLC is presented. We also demonstrate our recent experiment results including bidirectional 100 Mbit/s VLAN or Li-Fi system based on OOK modulation without blue filter. The VLC systems that we proposed are good solutions for high-speed VLC application systems with low-cost and low-complexity. VLC technology shows a bright future due to its inherent advantages, shortage of RF spectra and ever increasing popularity of white LEDs.     

GaAs/AlGaAs多量子阱FET-SEED灵巧象元

将GaAs／AlGaAs多量子阱光探测器、光调制器与GaAs场效应晶体管（FET）混合集成,构成FET-SEED灵巧象元。光探测器和光调制器均为反射型自电光效应器件（SEED）,光源为骨子阱半导体激光器。测出的光输出Pout／光输入Pin特性表明,光输入信号对光输出信号有明显的调制作用,光输入信号较小的变化可以导致光输出信号较大的变化。     

近红外波段二维环形光子晶体

提出了带隙在近红外波段的环形光子晶体,主要有一系列环形的孔在背景材料为GaAs上构成.发现带隙不依赖于入射方向,很少的几排即可在透过谱上产生带隙.六角形构成的环形光子晶体的S波和P波的透过谱显示有一个完全带隙存在,带宽-带隙中心比率高达11%.     

应用于千兆以太网的1-Gb/s 零极点对消CMOS跨阻放大器

A zero-pole cancellation transimpedance amplifier（TIA）has been realized in 0.35μm RF CMOS technology for Gigabit Ethernet applications.The TIA exploits a zero-pole cancellation configuration to isolate the input parasitic capacitance including photodiode capacitance from bandwidth deterioration.Simulation results show that the proposed TIA has a bandwidth of 1.9 GHz and a transimpedance gain of 65 dB·Ωfor 1.5 pF photodiode capaci- tance,with a gain-bandwidth product of 3.4 THz·Ω.Even with 2 pF photodiode capacitance,the bandwidth exhibits a decline of only 300 MHz,confirming the mechanism of the zero-pole cancellation configuration.The input resis- tance is 50Ω,and the average input noise current spectral density is 9.7 pA/√ Hz.Testing results shows that the eye diagram at 1 Gb/s is wide open.The chip dissipates 17 mW under a single 3.3 V supply.     

光子晶体垂直腔型表面发射和接收光电子器件

介绍了制作光子晶体垂直腔面发射激光器实验研究的主要内容,包括材料的光谱测试分析、氧化工艺以及制作光子晶体等,成功制作了波长在980nm附近的光子晶体垂直腔面发射激光器.在此基础上,采用高精度湿法腐蚀和感应耦合等离子体干法刻蚀技术,研究制作了基于垂直腔面发射激光器外延材料的光子晶体谐振腔增强型探测器.     

n型AlxGa1-xN材料的电学和光学性质

文章介绍了无裂纹高导电性n型A lxGa1-xN的MOCVD生长及其电学、光学和表面形貌性质。通过A lN两步生长法,有效地解决了A lxGa1-xN外延薄膜易裂的难题。并且对其生长进行优化,减少了A lxGa1-xN外延薄膜中的受主补偿缺陷,从而实现了高导电性的n型A lxGa1-xN薄膜,其载流子浓度为4.533×1018cm-3,并且电子迁移率高达77.5cm2/V.s,已经达到了目前国际上报道的先进水平。另外光学吸收谱说明A lxGa1-xN外延薄膜在302nm处具有陡峭的带边吸收,同时结合原子力显微镜分析材料的表面形貌,证实了材料表面光滑且平整。     

气源MBE外延自组装GeSi量子点光致荧光研究

利用气源分子束外延设备（MBE）制作了GeSi自组装量子点样品。利用原子力显微镜（AFM）和光致荧光（PL）光谱研究了量子点的形貌和光学性质。气源MBE在较低温度下生长的量子点材料具有较高的量子点覆盖度。200K以下载流子以局域激子形式束缚在量子点中,激子束缚能约为17meV。升温至200K,载流子的输运过程发生变化。对量子点PL积分强度与温度关系曲线进行拟合得到量子点中空穴跃迁至浸润层的热激活能为129meV。     

Fabrication of 4-Inch Nano Patterned Wafer with High Uniformity by Laser Interference Lithography

We report the fabrication of 4-inch nano patterned wafer by two-beam laser interference lithography and analyze the uniformity in detail. The profile of the dots array with a period of 800 nm divided into five regions is characterized by a scanning electron microscope. The average size in each region ranges from 270 nm to 320 nm,and the deviation is almost 4%, which is approaching the applicable value of 3% in the industrial process. We simulate the two-beam laser interference lithography system with MATLAB software and then calculate the distribution of light intensity around the 4 inch area. The experimental data fit very well with the calculated results. Analysis of the experimental data and calculated data indicates that laser beam quality and space filter play important roles in achieving a periodical nanoscale pattern with high uniformity and large area. There is the potential to obtain more practical applications.     

热超声倒装焊在制作大功率GaN基LED中的应用

设计了适合于倒装的大功率GaN基LED芯片结构,在倒装基板硅片上制作了金凸点,采用热超声倒装焊接(FCB)技术将芯片倒装在基板上.测试结果表明获得的大面积金凸点连接的剪切力最高达53.93 g/bump,焊接后的GaN基绿光LED在350 mA工作电流下正向电压为3.0 V.将热超声倒装焊接技术用于制作大功率GaN基LED器件,能起到良好的机械互连和电气互连.