Simultaneous Control of Light Polarization and Phase Distributions Using Plasmonic Metasurfaces

Harnessing light for modern photonic applications often involves the control and manipulation of light polarization and phase. Traditional methods require a combination of multiple discrete optical components, each of which contributes to a specific functionality. Here, plasmonic metasurfaces are proposed that accomplish the simultaneous manipulation of polarization and phase of the transmitted light. Arbitrary spatial field distribution of the optical phase and polarization direction can be obtained. The multifunctional metasurfaces are validated by demonstrating a broadband near‐perfect anomalous refraction with controllable linear polarization through introducing a constant phase gradient along the interface. Furthermore, the power of the proposed metasurfaces is demonstrated by generating a radially polarized beam. The new degrees of freedom of metasurfaces facilitate arbitrary manipulation of light and will profoundly affect a wide range of photonic applications.     

亚100nm体硅MOSFET集约I-V模型

利用“局域化”的概念和二维泊松方程的解析解，建立了沟道方向上二维量子效应对阈电压的修正模型．基于密度梯度理论，建立了多晶硅栅内量子效应对阈电压的修正模型．在此基础上，结合弹道理论，开发了一个适用于亚100nm MOSFET的集约I-V模型．通过与TSMC提供的沟长为45nm实际器件测试结果，以及与三组亚100nm MOSFET的数值模拟结果的比较，证明了该模型具有良好的精度（平均误差小于8%）和可延伸性．     

宽带偏振不灵敏InGaAs半导体光放大器

采用压应变InGaAs量子阱和张应变InGaAs准体材料交替混合的有源结构，研制了宽带偏振不灵敏的半导体光放大器．此放大器在100～250mA的工作电流范围内，获得了大于70nm的3dB光带宽；在0～250mA工作电流和3dB光带宽波长范围内，偏振灵敏度小于1dB．对于1.55μm的信号光，在200mA的注入电流下获得了15.6dB的光纤到光纤的增益、小于0.7dB的偏振灵敏度和4.2dBm的饱和输出功率．     

10Gb/s EML Module Based on Identical Epitaxial Layer Scheme

A 10Gb/s transmitter module containing an electroabsorption modulator monolithically integrated with a distributed feedback (DFB) semiconductor laser is fabricated using the identical epitaxial layer scheme.Gain-coupling mechanism is employed to improve the single mode yield of the DFB laser,while inductively coupled plasma dry etching technique is utilized to reduce the modulator capacitance.The integrated device exhibits a threshold current as low as 12mA and an extinction ratio over 15dB at －2V bias.The small signal modulation bandwidth is measured to be over 10GHz.The transmission experiment at 10Gb/s indicates a power penalty less than 1dB at a bit-error-rate of 1e－12 after transmission through 35km single mode fiber.     

Si基氨化ZnO／Ga2O3薄膜制备GaN纳米线

利用射频磁控溅射法在Si(111)衬底上溅射ZnO中间层和Ga2O3薄膜，然后在管式炉中常压下通氨气对ZnO/Ga2O3薄膜进行氨化，高温下ZnO层在氨气气氛中挥发，而Ga2O3薄膜和氨气反应合成出GaN纳米线．X射线衍射测量结果表明利用该方法制备的GaN纳米线具有沿c轴方向择优生长的六角纤锌矿结构．利用扫描电子显微镜、透射电子显微镜、傅里叶红外透射谱、能量弥散谱及选区电子衍射观测并分析了样品的形貌、成分和晶格结构．研究发现ZnO层的挥发有利于Ga2O3和NH3反应合成GaN纳米线．     

数字射频存储器用GaAs超高速3bit相位ADC的设计与实现

详细讨论、分析了用于3bit相位体制数字射频存储器（DRFM）系统的3bit相位体制ADC的设计、实现及测试．利用南京电子器件研究所标准GaAs Φ76mm全离子注入工艺，采用全耗尽非自对准MESFET器件加工实现了3bit超高速相位体制ADC．测试结果表明，该电路可在2GHz时钟速率下完成采样、量化，达到1.2Gbps的输出码流速率，其瞬时带宽可达150MHz，具备±0.22LSB的相位精度．     

Capacitive Microwave MEMS Switch

A novel capacitive microwave MEMS switch with a silicon/metal/dielectric as a membrane is fabricated successfully by bonding and etching-stop process.Its principal,design,and fabricating process are described in detail.A patterned dielectric layer,Ta2O5,with dielectric constant of 24 is reached.Experiment results show this novel structure,where the switch’s dielectric layer is not prepared on the transmission line,features very low insertion loss.The insertion loss is 0.06dB at 2GHz and lower than 0.5dB in the wider range from DC up to 20GHz,especially when the transmission line metal is only 0.5μm thick.     

应用ANN的数字信号调制模式识别的特征矢量分析

数字信号调制模式的自动识别是无线通信中信号分析和处理的关键步骤之一。神经网络应用于数字信号调制模式识别的一个重要的预处理过程就是要形成完备的特征矢量空间。本文在原有分析方法的基础上，研究了信号的瞬时特征、谱特征和统计特征，特别提出了用于信号子类分析的新的高阶统计量特征，形成了数字调制模式自动识别的较为完备的特征矢量空间。通过对九种数字调制信号进行仿真表明，即使在信噪为5dB的条件下仍然能够获得较高的识别正确率。     

掺Er3+碲铌酸盐玻璃的发光特性研究

以TeO2,Nb2O5,ZnO,Na2O为基质原料制备了掺铒碲铌酸盐玻璃,差热分析表明,Nb2O5的加入可以明显提高碲酸盐玻璃的热稳定性。同时应用McCumber原理计算的结果显示,摩尔分数为4%的Nb2O5的加入可使碲酸盐玻璃在1.53μm处的受激发射截面提高8%,其峰值达8.9×10-21cm2,而受激发射截面的有效带宽几乎不变。     

不同的外部光反馈强度下外腔半导体激光器大信号调制特性

基于等效腔理论,计及光线在外腔中多次反馈的情况后,从理论上研究了不同的反馈强度下,外腔半导体激光器(ECSL)的大信号调制特性。数值模拟的结果表明:当外部光反馈非常强或非常弱时,调制深度在一个较大的变化范围之内,ECSL的光子数呈现单周期变化规律,且峰值光子数随调制深度呈现单调上升的趋势;当外部光反馈处于中度反馈时,当调制深度取不同值时,ECSL的光子数呈现单周期、多周期甚至混沌现象。