4 × 20 GHz silica-based AWG hybrid integrated receiver optical sub-assemblies

Both the 4 × 20 GHz coarse wavelength division multiplexing and LAN-WDM receiver optical sub-assemblies(ROSAs) were developed. The ROSA package was hybrid integrated with a planar lightwave circuit arrayed waveguide grating(AWG) with 2% refractive index difference and a four-channel top-illuminated positive-intrinsicnegative photodetector(PD) array. The output waveguides of the AWG were designed in a multimode structure to provide flat-top optical spectra, and their end facet was angle-polished to form a total internal reflection interface to realize vertical coupling with a PD array. The maximum responsivity of ROSA was about 0.4 A/W, and its 3 dB bandwidth of frequency response was up to 20 GHz for each transmission lane. The hybrid integrated ROSA would be a cost-effective and easy-assembling solution for 100 Gb E data center interconnections.     

基于绝缘硅的微环谐振可调谐滤波器

采用电子束光刻和感应耦合等离子刻蚀等工艺,研制了一种基于绝缘硅材料的的微环谐振可调谐滤波器.滤波器微环半径为5μm左右,波导截面尺寸为(350～500 nm)×220 nm不等.测试结果表明,波导宽度为450 nm时器件性能最为理想,其自由频谱宽度为16.8 nm,1.55μm波长附近的消光比为22.1 dB.通过对微...     

硅基光波导化学传感器研究

研究了基于硅基集成光波导的马赫-曾德干涉仪(MZI)型化学传感芯片的设计、制备及相关敏感特性的模拟和分析.传感芯片采用硅基二氧化硅光波导材料,利用与传统互补型金属氧化物半导体(CMOS)兼容的工艺技术制作.通过波导的单模设计以及对MZI结构的优化,获得了有效折射率分辨率达到10-7量级的高灵敏度传感芯片.作为化学传感器,把MZI的其中一臂设计成传感臂.并进行适当的表面修饰,可制作出高灵敏度的干涉型光波导化学传感器.最后,对该传感器的折射率分辨率、敏感特性等进行了分析、模拟,同时,对面临的关键问题进行了分析和讨论.     

利用垂直腔表面发射激光器注入锁定实现上变频

提出了一种基于垂直腔表面发射激光器(VCSEL)的无本振光子微波上变频方案。该方案将相对低速的伪随机基带信号注入VCSEL中,利用注入信号的高次谐波注入锁定VCSEL。被锁定激光器波长与原注入光信号在谐振腔中相干差拍,产生上变频调幅微波信号。实验中利用2.5Gb/s非归零码强度调制信号注入锁定VCSEL,无需本振,实现了载波频率为14.3GHz的光子微波上变频,10kHz偏移处载波相位噪声达-81dBc/Hz。通过调节注入光信号的波长和功率,进一步实现载波频率在7.5~23GHz之间的调谐,验证了该方案的可行性,并对系统性能进行了误码分析,系统代价为1.4dB。结果证明该方案无需微波本振,仅需采用价格低廉的VCSEL即可实现光子微波上变频,从而为无线光混合接入网中光子微波信号产生技术提供了一种低成本的解决思路。     

Fabrication of Triplexers Based on Flattop SOI AWG

A triplexer is fabricated based on SOI arrayed waveguide gratings （AWGs）. Three wavelengths of the triplexer operate at different diffraction orders of an arrayed waveguide grating. The signals of 1490nm and 1550nm, which are input from central input waveguide of an AWG, are demultiplexed and the signal of 131Onto, which is input from central output waveguide of an AWG, is uploaded. The tested results show that the downloaded and uploaded signals have fiat-top response. The insertion loss is 9 dB on chip, the nonadjacent crosstalk is less than -30 dB for 1490nm and 1301 nm, and is less than -25 dB for 1550nm, the 3dB bandwidth equates that of the input light source.     

硅基二氧化硅波导阵列相位控制芯片

设计并制作了硅基二氧化硅波导阵列相控芯片,该芯片由分束单元、相位调制单元、输出波导阵列三部分构成,分束单元采用三级1×2的光分束器级联而成,相位调制单元采用热光调制方式,输出部分包含8根密集阵列波导.8根波导输出的光在远场发生干涉,形成扫描光束,加电后通过二氧化硅热光效应,折射率变化0.027%(0.000 4)时,扫描光束偏转5.5°.该波导相控阵列采用2.0%超高折射率差的硅基二氧化硅波导为材料,经等离子体增强化学气相沉积法进行材料生长及退火,再经电感耦合等离子体干法刻蚀技术进行刻蚀,最后切割抛光制作而成.测试结果表明,静态下该芯片8条输出阵列波导形成清晰干涉光斑,在电压达到130V时,热调制相位后,光斑移动5.5°.     

硅基二氧化硅光波导器件偏振特性的理论分析

从理论上分析了硅基二氧化硅光波导器件的芯区尺寸、相对折射率差、内应力和弯曲径对器件偏振特性的影响,得出结论：小折射率差的正方形波导的双折射系数小;内应力对双折射的影响比几何参数大;弯曲半径较小时,双折射系数较大,弯曲损耗也较大。     

材料力学性能检测虚拟实验的设计和开发

针对传统材料实验教学的种种弊端,将虚拟现实技术运用到材料实验教学当中,使教学过程具有交互性好,实验沉浸感强的特点。介绍了基于VRML的材料力学性能检测虚拟实验的设计思想和设计原理,对关键技术进行了阐述和分析。采用Pro/E、3DS MAX建立拉伸机、冲击机,疲劳试验机、压缩机、带表卡尺等实验仪器、工具的三维模型,并将其转换成VRML格式。然后通过VRML的事件路由机制实现了材料力学性能检测实验的全过程,如拉伸实验中,包括试样的测量、加载,拉伸过程的实现和曲线实时生成。作为材料实验教学的辅助工具,使学习过程形象化,充分发挥学生主观能动性,培养创新意识和解决工程问题能力。     

Fabrication of a novel silica PLC hybrid integrated triplexer

<正>A new-style silica planar lightwave circuit(PLC) hybrid integrated triplexer,which can demultiplex 1490- nm download data and 1550-nm download analog signals,as well as transmit 1310-nm upload data,is presented.It combines SiO_2 arrayed waveguide gratings(AWGs) with integrated photodetectors(PDs) and a high performance laser diode(LD).The SiO_2 AWGs realize the three-wavelength coarse wavelength-division multiplexing(CWDM).The crosstalk is less than - 40 dB between the 1490- and 1550-nm channels, and less than - 45 dB between 1310- and 1490- or 1550-nm channels.For the static performances of the integrated triplexer,its upload output power is 0.4 mW,and the download output photo-generated current is 76μA.In the small-signal measurement,the upstream -3-dB bandwidth of the triplexer is 4 GHz,while the downstream -3-dB bandwidths of both the analog and digital sections reach 1.9 GHz.     

Design and numerical analysis for low birefringence silica on silicon waveguides

A new fabrication technology for three-dimensionally buried silica on silicon optical waveguide based on deep etching and thermal oxidation is presented.Using this method,a silicon layer is left at the side of waveguide.The stress distribution and effective refractive index are calculated by using finite element method and finite different beam propagation method,respectively.The results indicate that the stress of silica on silicon optical waveguide fabricated by this method can be matched in parallel and vertical directions and stress birefringence can be effectively reduced due to the side-silicon layer.