离散谱折射率法优化设计MMI型光功分器

采用离散谱折射率法直接对三维脊形自镜像效应(SIE)多模波导的模式特性进行具体分析,并根据模式传播常数偏差分布情况,引入了SIE多模波导长度微小变量用以抵消或部分减弱由各阶模式传播常数偏差引起的相位偏差,设计了一种低自镜像损耗、高均匀度、几乎与偏振无关及深刻蚀SIE多模波导结构的多模干涉(MMI)光功分器。如1×16MMI光功分器TE模的自镜像损耗为0.0451dB,均匀度0.0309dB;对TE模的自镜像损耗为0.0455dB,均匀度为0.0311dB。     

多模干涉型双波长光功分器的设计与研究

研究了一种多模干涉型双波长光功分器,该器件可同时实现1．30μm、1．55μm波长的光信号功率分配。采用导模传输分析法,给出了该光功分器的工作原理,进而完成该功分器的设计。根据所确定的器件结构参数,结合器件制作过程中可能遇到的因素,详细分析了器件结构参数对器件性能的影响。经优化设计的双波长光功分器多模波导的宽度为28μm．长度为2735μm。两波长的插入损耗分别为0．59dB和0．41dB,两波长的功率离散分别为0．16dB和0．15dB。     

离子交换制作0.85μm MMI光功分器的仿真研究

提出了利用离子交换技术制作多模干涉(MMI)型光功分器的设计方法.以1×8MMI光功分器为例,采用导模传输分析法分析了器件基本原理,对离子交换制作波导的折射率分布进行了讨论.针对工作波长为0.85μm的1×8MMI光功分器结构参数进行了设计,对器件输出特性、各项技术指标、离子交换决定的折射率差Δn对器件性能的影响均进行了BPM仿真,结果表明:利用离子交换方法制作MMI型光功分器,设计指标可达到均匀性约0.009dB、平均插入损耗约9.111dB和最大插入损耗约9.116dB,均优于现有器件的指标.     

玻璃基片上双层多模光波导的制备

在光学玻璃基片上制作了双层掩埋式多模光波导芯片,这种芯片中的上、下两层光波导均通过熔盐离子交换和电场辅助离子迁移形成。对光波导的横截面以及输出光斑进行了观察,并进行了损耗和串扰测试。研究结果表明:双层多模光波导芯片中上、下两层光波导芯部横截面尺寸分别为29 m19 m和31 m20 m;两层波导的输出光斑尺寸相互匹配;两层波导传输损耗分别为1.000.32 dB/cm和0.780.35 dB/cm;两层光波导之间的串扰在17.7dB左右。这种玻璃基片上的双层多模光波导可以使板级光互连的互连密度增大一倍,提高EOCB的性能。     

湿法腐蚀制备的SOI光波导

用化学湿法腐蚀的方法制作了SOI光波导,并且用三维波束传播方法分析和设计了单模波导和1×2 3dB多模干涉分束器,修正了有效折射率和导模传输方法的误差.制作的器件具有低传输损耗(-1.37dB/cm)、低附加损耗(-2.2dB)、良好的均衡性(0.3dB)等优良性能.     

湿法腐蚀制备的SOI光波导

用化学湿法腐蚀的方法制作了SOI光波导,并且用三维波束传播方法分析和设计了单模波导和1×2 3dB多模干涉分束器,修正了有效折射率和导模传输方法的误差.制作的器件具有低传输损耗(- 1 37dB/cm)、低附加损耗(- 2 2dB)、良好的均衡性(0 3dB)等优良性能.     

基于MMI的聚合物1×16光功分器的设计及飞秒激光制备

高传输损耗和器件尺寸是限制光通信系统性能的关键问题,为此以光束传播法(BPM)设计仿真、利用飞秒超快加工技术制备了基于多模干涉耦合器(MMI)的聚合物1×16光功分器,器件尺寸小于22000μm。仿真结果表明平均插入损耗小于23dB,均匀性1.27dB。测试在1550nm波段,1×16光功分器平均插入损耗小于23dB,均匀性1.48dB。基于SU8胶材料仿真了用于光电电路板垂直耦合的光波导结构,利用时域有限差分法(FDTD)分析空间位置偏差对光纤与45°微反射镜的耦合效率影响,得到最佳耦合位置和最大耦合效率86.1%。结果表明器件具有易制备,较低的制备容差敏感度和结构紧凑的优点,符合光电集成和批量生产要求,对光分路器的设计和生产工艺有一定的参考价值。     

1 ×8MMI型玻璃基光功分器的研制

针对Ag+ - Na+离子交换形成的渐变折射率分布,分析了多模干涉(MM I)型功分器的 工作原理。在K9玻璃衬底上设计并制作了掩埋型1 ×8MM I功分器。测试结果表明,这种结构在具有结构紧凑、制作容差性大等优点的同时,其功分均匀性也很好,小于0. 5dB。     

玻璃基光功分器的小型化设计与制作

为满足光功分器的小型化和高性能化的需求,设计了长度为25 mm的1×16和1×32光功分器.在玻璃基片上利用一次Ag+-Na+离子交换和二次电场辅助离子扩散技术对所设计的光功分器进行了实验制作,并对器件的损耗性能进行测试.测试结果表明:1×16右分支的插入损耗9.87～10.84 dB,附加损耗0.87～1.84dB,均匀性0.97 dB.     

一种新型2×2 SOI热光开关

设计并制作了一种新型的SOI 2×2马赫-曾德(MZ)热光开关.这种光开关采用了深刻蚀结构的配对多模干涉耦合器,同时,为了保证单模传输和调制,在连接波导和调制臂区域采用了浅刻蚀结构.深刻蚀结构增强了多模干涉耦合器对光场的限制,有利于自映像质量的提高,从而减少了自映像损耗和不均衡度,同时也提高了制作容差.基于强限制配对干涉耦合器的新型热光开关,其插入损耗为-11.0 dB,其中包括光纤-波导耦合损耗-4.3 dB,上升和下降开关时间分别为3.5μs和8.8μs.     

Silica-based circular cross-sectioned channel waveguides

A technique for fabricating silica channel waveguides with circular cross sections is presented. The geometrical mismatch between a square or rectangular waveguide and a regular optical fiber is therefore largely reduced. The fiber-waveguide-fiber coupling loss drops from 1.8 dB to 0.5 dB or less for step index multimode waveguides by applying this technique. The heat treatment applied in the waveguide rounding process also smooths the waveguide sidewalls and results in much lower propagation loss in the waveguides. Uniform Y splitters were fabricated to show the feasibility of using this technique to make integrated optical devices.<>     

用于光互连的聚硅氧烷脊型光波导研究

采用软成型和图案转移技术,制备了可用于高速芯片间光互连的大尺寸聚硅氧烷脊型光波导,光波导长度达23cm.利用有效折射率法,对芯层残留层和传输模场的关系进行了分析.采用截断和数字化散射两种方法,测得输入光波长为633nm时的平均传输损耗小于0.14dB/cm.研究结果表明,波导的长度和损耗指标满足高速芯片间光互连的要求.     

采用多模输入/输出波导的多模干涉型SOI分束器

一个适用于光纤通信系统中的1×8多模干涉功率分束器被设计并通过ICP刻蚀方法成功研制.这种基于SOI材料的功率分束器是采用多模波导作为输入/输出波导;经过光束传播方法模拟,该器件显示出了优良的性能.测试结果表明,在1550nm波长处器件的传波损耗低于0.80dB,损耗均匀性为0.45dB,而且偏振相关损耗低于0.70dB.器件的尺寸只有2mm×10mm.     

Low-loss polymeric optical waveguides fabricated with deuteratedpolyfluoromethacrylate

Deuterated polyfluoromethacrylate which has high transparency, low birefringence and good processability was newly synthesized for use as optical waveguide materials, and both single-mode and multimode optical waveguides were fabricated using the polymer. The propagation loss and waveguide birefringence of the single-mode waveguides were as low as 0.10 dB/cm and -5.5×10^-6 at 1.31 μm, respectively. The propagation losses of the multimode waveguides were less than 0.02 dB/cm at both 0.68 and 0.83 μm, and 0.07 dB/cm at 1.31 μm     

Stacked polymeric multimode waveguide arrays for two-dimensional optical interconnects

Two-dimensional (2-D) polymeric multimode waveguide arrays with two reflection-mirrors have been fabricated for optical interconnects between 2-D arrayed vertical-cavity surface-emitting lasers and detectors. Contact printing lithography was adopted for simple and low-cost process using ultraviolet-curable epoxy-based polymers. Fabricated waveguides were diced of the same size and stacked one by one with lateral positional errors less than /spl plusmn/20 /spl mu/m. Two kinds of mirrors were fabricated: single-reflection mirror and double-reflection mirror. Double-reflected mirrors resulted in lower losses with 1.2 dB than single reflected mirrors with 2.1 dB. The average insertion losses of 16-channel arrayed waveguides with two single-reflection mirrors and with two double-reflection-mirrors were measured to be 6.1 and 4.4 dB for 6-cm-long waveguides at a wavelength of 830 nm, respectively. The crosstalk between the waveguides was less than -25 dB. The characteristics of the waveguide arrays are good enough for applications to optical interconnects.     

GaAs/GaAlAs curved rib waveguides

Curved dielectric optical waveguides suffer from radiation loss due to bending. To minimize the bending loss and reduce the radius of curvature, it is necessary to fabricate guides which provide strong optical confinement. This paper gives a brief review of curved waveguide analysis and presents some experimentally measured loss values for GaAs/GaAlAs curved rib waveguides. The rib waveguides, fabricated using ion beam milling, have a large rib height and are tightly guided structures. When corrected for reflection losses and input coupling efficiency, a minimum loss of approximately 3 dB has been achieved for a multimode 90° curved guide with a radius of curvature of 300 μm, and 8.5 dB for a single-mode curved guide with a radius of curvature of 400 μm. It is believed that most of this residual loss is not radiation loss due to bending, but rather scattering loss due to rib wall imperfections.     

Optimization of silicon-on-insulator based optical switch using tapered waveguides

Optimized 2×2 switches based on silicon-on-insulator (SOI) were demonstrated. In the design, single mode rib waveguidesand multimode interferences (MMIs) are connected by tapered waveguides to reduce the mode coupling loss between thetwo types of waveguides. The average insertion loss of the switches is about -16.9 dB and the excess loss of one is measuredof -1.3 dB. The worst crosstalk is larger than 25 dB. Experimental results indicate that some of the main characteristics ofoptical switches are improved in the modified design, which is according with theoretic analysis. The novel design can beused to improve the characteristics of optical switch matrixes based on 2×2 switch units.     

Active lossless monolithic one-by-four splitters/combiners usingoptical gates on InP

Active one-by-four splitters/combiners were fabricated on InP from the monolithic integration of waveguides and amplifiers. The device exhibited propagation loss below 1.5 dB·cm^-1, S-bend loss of 0.2 dB per bend, a 3-dB optical bandwidth of 23 nm, a mean optical crosstalk and extinction ratio of, respectively, 37 dB and 42 dB. On all paths, at least 0 dB insertion loss (fiber to-fiber gain up to 2.8 dB) as well as a low polarization sensitivity (below 1.0 dB) were demonstrated. This device can be used as the basic building block of bit-rate transparent switches for optical routing and broadcasting     

Integrated optical beam splitters formed in glass channel waveguides having variable weighting as determined by mask dimensions

Variable-weight beam splitters integrated into glass channel optical waveguides have been fabricated and successfully operated. Variable weighting is achieved by varying mask dimensions. Beam splitting is achieved by introducing notched reflectors of variable size into glass channel waveguides which are formed in shallow grooves having trapezoidal cross sections on silicon substrates. Preferential etching is used to fabricate these grooves and notches. A novel lift-off method incorporating a photoresist, glass, and aluminum sandwich structure is introduced to define glass channel waveguides having smooth edges within the grooves. The extent of the beam splitting notch as determined by scanning electron microscope observation is shown to correspond directly with measured beam splitting ratios for four different ratios. An insertion loss of 0.34 dB is measured for one of the samples.     

Low-loss singlemode amorphous silicon waveguides

Amorphous silicon waveguides were obtained by plasma-enhanced chemical vapour deposition and anisotropic plasma etching. Rectangular multimode waveguides as well as singlemode ridge waveguides were fabricated. Scattered light measurements at 1550 nm (1300 nm) wavelength showed a low propagation loss of /spl les/0.5 dB/cm (1.6 dB/cm) for multimode waveguides and 2.0 dB/cm (5.0 dB/cm) for highly-confined singlemode waveguides.