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.     

A concise design of 16 × 16 polymer AWG with low insertion loss and crosstalk

In this paper, a 16-channel arrayed waveguide grating multiplexer (AWG) has been designed using polymer materials with 1.5% refractive index difference. Certain important parameters are optimized using the coupling mode theory and Beam Propagation Method. The factors that affect the insertion loss and the crosstalk are analyzed in this paper. In our design we introduced the parabolic taper structure and evaluated the suitable number of the arrayed waveguide, obtaining a total insertion loss of 2.19 dB. For obtaining a low crosstalk we evaluate the pitches of adjacent input/output waveguides ΔX and arrayed waveguides d as different values. We chose the value of ΔX about 2.5 times of d by enlarging the pitches of adjacent input/output waveguides. The crosstalk of the designed AWG is lower than −40 dB.     

Compact SOI arrayed waveguide grating demultiplexer with broad spectral response

A compact eight-channel flat spectral response arrayed waveguide grating (AWG) multiplexer based on silicon-on-insulator (SOI) materials has been fabricated on the planar lightwave circuit (PLC). The 1-dB bandwidth of 48 GHz and 3-dB bandwidth of 69 GHz are obtained for the 100 GHz channel spacing. Not only non-adjacent crosstalk but also adjacent crosstalk are less than −25 dB. The on-chip propagation loss range is from 3.5 to 3.9 dB, and the total device size is 1.5 × 1.0 cm².     

减少聚合物阵列波导光栅损耗的蒸气回溶技术

阵列波导光栅(AWG)器件是波分复用(WDM)系统的一种关键器件,其中,聚合物阵列波导光栅由于其制备工艺、器件集成等方面的优势而受到人们的日益关注。侧壁散射损耗是聚合物阵列波导光栅损耗的一个主要因素,减少阵列波导光栅波导的侧壁损耗对制备低损耗阵列波导光栅具有重要意义。一种蒸气回溶技术被用来有效地减少硅基聚合物阵列波导光栅的散射损耗,该技术的机理是饱和溶剂分子融入并软化波导侧壁,增加其流动性,从而降低波导侧壁粗糙度。用扫描电镜方法验证了用该技术能获得更光滑的波导侧壁。对直波导和阵列波导光栅样品进行回溶处理,测试后得到直波导的侧壁散射损耗减少2.1 dB/cm,阵列波导光栅中心信道和周边信道的插入损耗分别减少5.5 dB和6.7 dB,串扰减少2.5 dB。     

阵列波导光栅平坦化的研究

阵列波导光栅的平坦化在实际应用中有很重要的意义.本文系统地研究了阵列波导光栅的平坦化.在输入波导、输出波导、阵列波导输入端与输出端上分别引入了指数型锥形波导.通过改变锥形波导的形状和尺寸来实现平坦化的优化.本文首先从理论上论述了引入指数型锥形波导的输出光谱特性,给出了结构参量的关系表达式,阐明了输入波导处的锥形波导是影响输出光谱平坦化的主要因素,阵列波导和输出波导处的锥形波导对输出光谱的平坦化有一定的影响.其次采用数值模拟的方法模拟了输出光谱,优化了结构参量,总结出了指数型锥形波导对平坦化影响的趋势和规律.模拟结果显示,输出光谱1 dB带宽大于通道间隔的50%,插入损耗从5.2 dB减小到了4.0 dB,串扰小于-30 dB.最后,本文给出了实验结果,插入损耗减小了0.87 dB,串扰减小了3.67 dB,1 dB带宽增加0.1 nm,增加了54.7%.实验结果表明引入指数型锥形波导提高了阵列波导光栅器件的光谱性能.     

InP阵列波导光栅的误差分析

在InP阵列波导光栅的制作过程中会引入不同的误差,从而影响器件的性能.为了最大限度地控制误差,提高半导体器件性能,本文采用传输函数法对InP基阵列波导光栅的系统误差和随机误差分别进行了分析.从系统误差的模拟结果中可以得到如下结论:深脊型波导的有效折射率n_c平均每偏移+0.000 1,中心波长偏移+0.05nm.相邻阵列波导长度差ΔL每偏移+0.01 μm,中心波长将偏移+0.44 nm.n_c和ΔL仅仅会影响到传输谱中心通道及其他各通道对应的波长,使得传输谱发生整体漂移,而信道间隔及串扰不会改变.罗兰圆半径R偏移不会影响器件的中心通道对应的波长,但会使其它通道对应的波长发生变化,最终使得信道间隔改变,R增加50 μm,信道间隔减小0.03 nm.从随机误差模拟结果中,得出:波导芯区折射率、上包层折射率、衬底折射率、波导宽度和波导芯层厚度的随机波动会对阵列波导光栅的串扰产生较大的影响.根据以上分析,可以通过控制不同参量来调节器件的中心波长以及信道间隔等来优化阵列波导光栅的光学性能.     

A novel wavelength dispersive device with a dispersive element based on staircase-like straight and parallel arrayed waveguides

We propose a new type of arrayed waveguide grating (AWG) multiplexer/demultiplexer based on modified group refractive index. This device is composed by an array of straight and parallel waveguides of equal length and each waveguide consist of two sections with different width. The length of the two sections are changed from a waveguide to the adjacent one following a linear dependence resulting in a wavelength dispersive waveguide array. An example of the device design for silicon-on-insulator (SOI) platform is provided and numerical simulations have been carried out for various arrayed waveguide parameters. We demonstrate that the group index modification can be used for tailoring device dispersion properties, and that it can also result in new dispersion characteristics predicted numerically not observed in conventional AWGs. Additional advantages are that the demultiplexer does not necessarily require bending waveguide sections as in a conventional AWG (de)multiplexers, and thus yields highly compact devices with potentially very low insertion loss. Channel spacing of 1 nm have been predicted for sub-micron waveguides sizes. In this paper it is also proposed a novel wavefront converter based on waveguide array lens-like element with waveguides broadened sections. Numerical results for different input/output geometries are analized.     

不同结构SOI交叉波导的损耗及串扰特性研究

利用高阶Pade近似的2D-BPM算法,对具有不同弯曲半径及交叉角度的SOI弯曲交叉波导的传输特性进行了模拟、分析和深入研究,发现交叉波导的串扰随弯曲半径及交叉角度增大而减小的规律.在此基础上,对由正弦弯曲、余弦弯曲以及圆弧弯曲三种弯曲波导构成的SOI交叉波导的损耗及串扰特性进行了分析比较.结果表明,由正弦弯曲构成的交叉波导传输损耗最小且串扰最小.     

Eliminating the birefringence in silicon-on-insulator ridge waveguides by use of cladding stress

We propose and demonstrate the use of the cladding stress-induced photoelastic effect to eliminate modal birefringence in silicon-on-insulator (SOI) ridge waveguides. Birefringence-free operation was achieved for waveguides with otherwise large birefringence by use of properly chosen thickness and stress of the upper cladding layer. With the stress levels typically found in cladding materials such as SiO2, the birefringence modification range can be as large as 10(-3). In arrayed waveguide grating demultiplexers that were fabricated in a SOI platform, we demonstrated the reduction of the birefringence from 1.2 x 10(-3) (without the upper cladding) to 4.5 x 10(-5) when a 0.8-microm oxide upper cladding with a stress of -320 MPa (compressive) was used. Because the index changes induced by the stress are orders of magnitude smaller than the waveguide core-cladding index contrast, the associated mode mismatch loss is negligible.     

阵列波导光栅解调的准分布式光纤光栅传感器

从理论上和实验上研究了一种操作简单、响应速度快,价格低廉和高分辨率的基于阵列波导光栅(AWG)的准分布式光纤布拉格光栅(FBG)传感器.该传感系统采用了阵列波导光栅双通道强度解调技术对光纤光栅的布拉格波长和温度进行精确的解调.实验结果表明,该系统对宽带宽光纤光栅的布拉格波长和温度解调均具有高线性度,考虑系统稳定性及光纤布拉格光栅之间的串扰影响,波长测量精度仍可达2 pm,温度测量精度优于0.2℃.     

Waveguide structure optimization of arrayed waveguide gratings concatenation in cascaded optical add/drop multiplexers

The dimensions of input waveguide and output waveguide of arrayed waveguide gratings (AWGs) determine the crosstalk, insertion loss and 1-dB bandwidth. In cascaded optical add/drop multiplexers (OADMs), the value of these parameters will largely affect the power penalty of system. The power penalty of cascaded OADMs is calculated with different waveguide dimensions of AWGs in this paper. Considering of wavelength misalignment, an optimization design of AWGs is obtained.     

基于绝缘体上的硅材料的全内反射型阵列波导光栅器件的设计

设计了一种基于绝缘体上的硅材料的全内反射型阵列波导光栅解复用器年。将一全内反射波导镜引入原弯曲的波导列阵中，该波导镜具有偏振补偿的功能和缩小器件尺寸的特点。在器年数值模拟的基础上，制作了原理性器件，并获得了初步的实验结果。     

基于硅基二氧化硅阵列波导光栅宽带低串扰单纤三向器

采用硅基二氧化硅阵列波导光栅设计并制作了宽带低串扰单纤三向器.为使三个波长间隔相差较大的输出谱获得相同的带宽,在输出波导与罗兰圆交界采用了不同结构的多模干涉器.二维有限差分束传播法的模拟结果表明,理论上1310nm、1490nm和1550nm波长的3dB带宽分别达到23nm、23.5nm和25nm,插入损耗均为4dB,1310nm波长的串扰小于-40dB,1490nm与1550nm波长间串扰小于-40dB;采用宽带光源测试结果表明,1550nm波长的3dB带宽为23nm,采用三个独立窄带光源测试结果表明,三个波长的插入损耗均为7dB,1310nm波长的串扰小于-40dB,1490nm与1550nm波长间的串扰小于-39dB,测试与模拟结果基本一致.     

阵列波导光栅波分复用/解复用器光谱响应效率的理论模型

基于单模光波导的本征模场分布，瑞利－索末菲衍射积分公式和天线原理的互易定理，给出耦合器中两个非接触平面光波导耦合特性的描述.基此，根据等光程差不等振幅多光束干涉的光场叠加原理，推导出新颖的阵列波导光栅波分复用/解复用器的光谱响应效率的解析函数表达式，这些表达式可为快速精确分析阵列波导光栅波分复用/解复用器的特性提供理论基础.同时,介绍了一个计算阵列波导光栅波分复用/解复用器特性的例子，给出其光谱响应度和信号通道串扰.     

利用鞍点近似法计算串音对阵列波导光栅复用器性能的影响

基于光的波动性,考虑信号和串音偏振态,改进了鞍点近似法的数学模型,计算了阵列波导光栅复用器的误码率和功率代价,并与高斯近似法和实验结果进行了比较,显示出较高的计算精度。     

Design and characterization of arrayed waveguide gratings using ultra-low loss Si3N4 waveguides

Planar waveguides with ultra-low propagation loss are necessary for integrating optoelectronic systems that require long optical time delay or narrowband optical filters. In this paper, we review an ultra-low loss planar waveguide platform that uses thin (<150 nm) Si₃N₄ cores and thick (>8 μm) SiO₂ cladding layers. In particular, we discuss the performance of arrayed waveguide gratings (AWGs) fabricated with the platform. We propose the use of a practical design method that takes the statistical nature of worst-case crosstalk into account. We also demonstrate the measurement of amplitude and phase error distributions in an AWG using an optical backscatter reflectometer. We show that the waveguides have phase errors small enough to achieve AWG crosstalk below ?30 dB, while crosstalk below ?40 dB should also be possible with optimization of the component design.     

Electrochemical oxidation of methanol on Pt nanoparticles composited MnO2 nanowire arrayed electrode

By use of the membrane-template synthesis route, MnO₂ nanowire arrayed electrodes are successfully synthesized by means of the anodic deposition technique. The Pt nanoparticles composited MnO₂ nanowire arrayed electrodes (PME) are obtained through depositing Pt on MnO₂ nanowire arrayed electrode by cathode deposition technique. For comparison of electrochemical performance, Pt nanowire arrayed electrodes which have the same amount of Pt with PME are also prepared. The electro-oxidation of methanol on PME and Pt nanowire arrayed electrodes is investigated at room temperature by cyclic voltammetry, which show that about 110 mV decreased overpotential and 2.1-fold enhanced votammetric current are achieved on PME. The chronoamperometry result demonstrates that the resistance to carbon monoxide for PME is improved.     

O波段8通道硅基二氧化硅平坦化阵列波导光栅的设计及制备

设计并制作了一款应用于IEEE 200/400GbE标准802.3bs的阵列波导光栅.该阵列波导光栅使用2.0%的超高折射率差硅基二氧化硅材料,使得芯片尺寸及损耗较小.为了获得平坦化的接收光谱,将输出波导进行展宽,采用多模波导结构,激发若干个高阶模,数个模式叠加使得原本高斯状的光谱顶部产生平坦化,形成箱形接收光谱.设计的阵列波导光栅的中心波长为1 291.10nm,通道间隔为800GHz,芯片尺寸为11mm×4mm.经过等离子增强化学气相沉积和感应耦合等离子刻蚀工艺制备了芯片,测试结果表明最小的插入损耗为-3.3dB,相邻通道间串扰小于-20dB,单通道1dB带宽在2.12~3.06nm范围,实现了良好的解复用和平坦化效果,在实际光通信系统中有一定的实用价值.     

硅基二氧化硅波导和SOI脊型波导应力双折射研究

采用有限元方法分析了硅基二氧化硅波导和SOI（Silicon on Insulator）脊型波导内部残留热应力引起的双折射.对于硅基二氧化硅波导，应力双折射系数的数量级为10－4，对于上包层为空气的SOI脊型波导，该系数的数量级为10－5，对于上包层为SiO2的SOI脊型波导，该系数的数量级为10－3，可见在硅基二氧化硅波导和上包层为SiO2的SOI脊型波导中产生了大的应力双折射，而在上包层为空气的SOI脊型波导中应力双折射较小.     

阵列波导光栅线性系统理论分析及优化设计

运用线性系统理论分析了阵列波导光栅的模场特性 ,导出器件传输的数学模型即光栅方程。提出了设计阵列波导光栅阵列波导数M的新方法 ,该方法综合考虑了降低器件串扰以及收集发散光场的能力 ,与文献 [1 ]的方法相比简单且准确。分析了造成器件衍射损耗的原因 ,提出了降低器件衍射损耗的方法。给出了 8× 0 .8nm ,中心波长为 1 550nm的阵列波导光栅波分复用器的设计实例 ,并进行了数值模拟计算验证了文中所提方法的准确性。