基于LiNbO3调制器的40GHz宽带调制光源的设计

介绍了基于LiNbO3电光强度调制器的40GHz宽带调制光源的设计.对其中的关键技术,如直流激光器稳态工作、调制器输出功率稳定性、频率响应预失真补偿以及整体设计等逐一加以分析,并提出解决方案.成功实现了基于LiNbO3电光强度调制器的宽带调制光源,并对该高速光源进行了一系列性能和指标测试.光源的频率响应3dB带宽达到40GHz,可用于40GHz频率范围内光电子器件频率响应特性测试,同时也满足SDH/SONET传输实验要求.     

基于LiNbO3调制器的40GHz宽带调制光源的设计

介绍了基于LiNbO3电光强度调制器的40GHz宽带调制光源的设计.对其中的关键技术,如直流激光器稳态工作、调制器输出功率稳定性、频率响应预失真补偿以及整体设计等逐一加以分析,并提出解决方案.成功实现了基于LiNbO3电光强度调制器的宽带调制光源,并对该高速光源进行了一系列性能和指标测试.光源的频率响应3dB带宽达到40GHz,可用于40GHz频率范围内光电子器件频率响应特性测试,同时也满足SDH/SONET传输实验要求.     

用于40Gb/s光电子器件的新型低成本硅基过渡热沉

提出了一种新型低成本硅基过渡热沉,用以实现高达40Gb/s的高速光电子器件封装. 采用高阻硅衬底作为热沉基底,制作出了0～40GHz范围内传输损耗小于0.165dB/mm的共面波导传输线. 热沉中采用Ta2N薄膜电阻作为负载以实现器件的阻抗匹配,达到了0～40GHz范围内低于-18dB的宽带低反射特性. 和传统硅基平台相比,新型硅基热沉更具有制作工艺简单、导热性能良好等优点. 为了证明其实用性,热沉被应用于高速电吸收调制器的管芯级封装测试,获得了超过33GHz的小信号调制带宽特性,在硅基热沉上首次实现可用于40Gb/s系统的光电子器件.     

用于40Gb/s光电子器件的新型低成本硅基过渡热沉

提出了一种新型低成本硅基过渡热沉,用以实现高达40Gb/s的高速光电子器件封装.采用高阻硅衬底作为热沉基底,制作出了0～40GHz范围内传输损耗小于0.165dB/mm的共面波导传输线.热沉中采用Ta2N薄膜电阻作为负载以实现器件的阻抗匹配,达到了0～40GHz范围内低于-18dB的宽带低反射特性.和传统硅基平台相比,新型硅基热沉更具有制作工艺简单、导热性能良好等优点.为了证明其实用性,热沉被应用于高速电吸收调制器的管芯级封装测试,获得了超过33GHz的小信号调制带宽特性,在硅基热沉上首次实现可用于40Gb/s系统的光电子器件.     

10 Gb/s电吸收调制器的微波封装设计

在高速光电子器件的微波封装过程中，需要综合考虑封装寄生参数和芯片寄生参数对器件高频性能的影响。利用封装寄生参数对芯片寄生参数的补偿作用，成功实现了10Gb／s电吸收调制激光器（EML）的高频封装。通过封装前后芯片和器件的小信号频率响应测试结果对比，器件的反射参数和传输参数有所改善，3dB带宽达到10GHz；并进行了10Gb／s速率的光纤传输实验，经过40km光纤传输后通道代价不到1dBm（误码率为10^-12），满足10Gb／s长距离光纤传输系统的要求。     

10Gbit/s InGaAs/InP雪崩光电二极管

基于InGaAs/InP吸收区、渐变区、电荷区和倍增区分离雪崩光电二极管(SAGCMAPD)器件结构,利用数值计算方法,模拟了各层参数对器件频率响应特性的影响.模拟结果表明,吸收层、倍增层厚度及电荷层面电荷密度可影响器件的-3 dB带宽;随增益的增加,器件带宽会逐渐降低;电荷层面电荷密度对器件击穿电压有明显影响.结合此模拟结果,制作出了高速InGaAs/InP雪崩光电二极管,并对器件进行了封装测试.测试结果表明,该结果与模拟结果相吻合.器件击穿电压为30 V;在倍增因子为1时,器件响应度大于0.8 A/W;在倍增因子为9时,器件暗电流小于10 nA,-3 dB带宽大于10 GHz,其性能满足10 Gbit/s光纤通信应用要求.     

一种基于薄膜铌酸锂调制器芯片的新型电光调制器

针对传统铌酸锂电光调制器体积大、带宽小等技术问题,提出了一种基于薄膜铌酸锂调制器芯片的新型电光调制器的设计方法,给出了薄膜铌酸锂电光调制器高频传输仿真模型,详细介绍了薄膜铌酸锂电光调制器的高频信号馈入设计、过渡薄膜基板高频阻抗匹配设计,并测试了40 GHz小尺寸薄膜铌酸锂电光调制器的核心指标。测试结果表明：设计的薄膜铌酸锂电光调制器插入损耗、半波电压、3 d B带宽、产品尺寸分别为4.1 d B、3.9 V、40 GHz、30 mm×10 mm×5 mm,比传统铌酸锂电光调制器性能优越。     

高速InGaAs PIN光电二极管频率响应测试的新方法

对很高速率传输系统来说,需要发展高速光电探测器件,如何测量这些高速光电二极管(PD)的频率响应显得十分重要。然而在常规测试系统中,即直接使用光学信号调制或通过外调制的频率响应的测试方法受到激光器或调制带宽的限制,目前可测得的最大带宽为10GHz。通常测量PD的频率响应是以取样示波器为基础,而示波器的极限分辨能力仅为25ps,为了准确测量20ps或20ps以下的高速响应PD,这种方法显得不适应了。在PD的频     

一种渐变掺杂型pin光探测器的高速响应性能研究

高速光探测器是高速光纤通信系统和网络中的关键器件,它要求光探测器具有宽的频率响应带宽和高量子效率。垂直入光型pin光探测器的高速性能和量子效率均受到吸收层厚度的限制。为了改善其高速性能,采用InGaAsP材料作为吸收层以及限制层渐变掺杂的方法,对垂直入光型pin光探测器的高速响应性能进行了理论研究和仿真,结果表明,高速响应达到了40GHz。与不采用渐变掺杂浓度的同种结构光探测器相比,高速响应性能显著提高。     

宽带外调制模拟光发射机的设计

介绍了宽带外调制模拟光发射机的设计.对其中的关键技术,如直流激光器稳态工作、调制器最佳偏置点的稳定、频率响应补偿等逐一加以分析,并提出解决方案,成功实现了宽带外调制模拟光发射机,其频率响应1.5dB带宽达到3GHz,可用于雷达、微波等模拟信号的光发射,也可用于数字信号的光发射.     

Integrated-optic system for high-speed photodetector bandwidth measurements

A novel measurement system based on an integrated-optic modulator has been used to determine the frequency response of a high-speed GaInAs photodiode. A nominally 8 GHz bandwidth modulator provided a 3 mu W levelled, continuously tunable, modulated optical signal to greater than 21 GHz. The measured detector 3 dB bandwidth was 19.2+or-0.8 GHz.<>     

Optical Microwave Frequency Up-Conversion Via a Frequency-Doubling Optoelectronic Oscillator

We propose and demonstrate an optical microwave modulator that incorporates a low phase-noise optoelectronic oscillator (OEO) for frequency up-conversion in a radio-over-fiber system. A single Mach-Zehnder lithium-niobate waveguide modulator working as a local oscillator in a frequency-doubling OEO directly up-converts the baseband signals to a carrier band. We demonstrate frequency up-conversion to the 20-GHz band for optical analog signals in the intermediate-frequency (IF) band and for optical digital signals at 1.25 Gb/s. The measured transmission bandwidth for IF modulated signals is greater than 1.5 GHz for transmission over 50.5 km of single-mode fiber.     

全封装的薄膜铌酸锂电光调制器（特邀）

高速电光调制器是宽带光通信网络和微波光子系统中的关键元器件之一。相对于体材料铌酸锂而言,薄膜铌酸锂材料由于其较强的光场限制能力,在构建小尺寸、宽带、低半波电压的高性能电光调制芯片上有独特的优势。文章基于薄膜铌酸锂材料研制了一种3 dB带宽不低于50 GHz的电光调制芯片,并采用光纤与波导水平端面耦合的光学封装方案和基于1.85 mm同轴接头的射频封装方案,实现了全封装的薄膜铌酸锂电光调制器。测量结果表明,封装后器件的光学插入损耗小于等于5 dB,3 dB带宽大于等于40 GHz,射频半波电压小于等于3 V@1 GHz。     

应用于40Gb／s电吸收调制器的Al2O3高速热沉研究

设计制作了面向40Gb/s电吸收调制器(EAM)的高速微波过渡热沉,并进行了EAM管芯级封装测试的验证.这种基于氧化铝(A l2O3)的热沉采用共面波导(CPW)传输线以实现低损耗微波传送,以及Ta2N薄膜电阻用于EAM的阻抗匹配.采用Ti/Cu/N i/Au金属材料作为CPW传输线电极材料,从而保证CPW传输线与Ta2N电阻材料之间良好的电接触,使热沉的典型反射系数在0~40 GHz范围内均达到优于-21 dB的水平.作为验证,采用该种热沉用于高速EAM的管芯级封装,测试得到小信号调制响应带宽超过40 GHz.     

High-Speed Coplanar Waveguide Based Submount for 40 Gbit/s Electroabsorption Modulator

A high-speed submount has been designed and fabricated for 40 Gb/s electroabsorption (EA) modulators. The submount contains a coplanar waveguide (CPW) for microwave signal feeding and a Ta₂N thin-film resistor for impedance matching. The CPW transmission line is designed to ensure low microwave loss and reflection, and Ti/Cu/Ni/Au metal is adopted for electrode fabrication to guarantee good contact with the Ta₂N thin-film. The typical reflection coefficient of fabricated submount is estimated to be lower than?21 dB up to 40 GHz. As a demonstration, a high-speed EA modulator was chip-level packaged using the high-speed submount, and the measured small-signal modulation bandwidth was over 40 GHz.     

40 Gbit/s silicon optical modulator for highspeed applications

A high-speed silicon optical modulator based on the free carrier plasma dispersion effect is presented. It is based on carrier depletion of a pn diode embedded inside a silicon-on-insulator waveguide. To achieve high-speed performance, a travelling-wave design is used to allow co-propagation of the electrical and optical signals along the length of the device. The resulting modulator has a 3 dB bandwidth of ~30 GHz and can transmit data up to 40 Gbit/s.     

Integration and Characteristics of 40-Gb/s Electroabsorption Modulator Integrated Laser Module With a Driver Amplifier and Bias Tees

Integration of a 40-Gb/s electroabsorption modulator integrated distributed feedback (DFB) laser (EML) module with a driver amplifier and bias tee was investigated. For the EML fabrication the selective area growth (SAG) technique was adopted for the first time. It is shown that, with the SAG technique, the 3-dB bandwidth of about 45 GHz was measured in the electrical to optical response, and the return loss (S11) of below $-$10 dB was achieved for up to 50 GHz . To integrate a bias tee within the module, a right-angle bent coplanar waveguide (CPW) was developed. The right-angle bent CPW was characterized with S11 of below $-$ 10 dB for up to 35 GHz and insertion loss (S21) of about $-$1.4 dB for up to 40 GHz . The whole integrated module including the EML, a driver amplifier, and bias tee was characterized under the conditions of an operating temperature of 25 $^{circ}{rm C}$, the modulator bias of 1.4 V, and the DFB laser current of 40 mA. S11 of below $-$10 dB was obtained for up to 14 GHz and the measured electrical-to-optical response has 3-dB bandwidth of about 20 GHz.      

Optimization of Packaging Design of TWEAM Module for Digital and Analog Applications

Packaging technologies for a broadband and narrowband modulator with a traveling wave electroabsorption modulator (TWEAM) device were developed. In developing a broadband modulator, the effects of the device and packaging designs on the broadband performance were investigated. The optimized designs were obtained through a simulation with the result that we developed a broadband modulator with a 3 dB bandwidth of 38 GHz in the electrical‐to‐optical (E/O) response, an electrical return loss of less than ?10 dB at up to 26 GHz, an rms jitter of 1.832 ps, and an extinction ratio of 5.38 dB in a 40 Gbps non‐return to zero (NRZ) eye diagram. For analog application, the effect of the RF termination scheme on the fractional bandwidth was studied. The microstrip line with a double stub as a matching circuit and a laser trimming process were used to obtain an S11 of ?34.58 dB at 40 GHz and 2.9 GHz bandwidth of less than ?15 dB.     

利用基带直调信号注入锁定半导体激光器产生全光上变频信号的研究

提出了一种将低速基带信号直调产生的宽谱信号,注入至用于上变频的分布反馈式半导体激光器(DFB-LD),利用调制信号光谱中的高阶分量对从激光器进行相位锁定,从而产生光学上变频信号的方法。对直调信号注入锁定DFB-LD产生光学上变频信号的机理进行了理论分析,完成了2.5Gb/s伪随机码基带信号通过直调并注入从激光器,分别产生了30,35,40GHz副载波频率的全光上变频信号的实验,并在时域和频域上,对上变频信号的特征进行了研究。该方案结构简单,无需高速外调制器及高频本振,具有集成潜力,理论上可产生更高载频(如60GHz),对目前的光-无线混合接入提供了一种可行的解决方案。