考虑光强分布的光通信光栅列阵光束整形方法

光栅单元阵列由大量的单元组成,每个单元的大小和形状都需要精确控制,以确保光束的整形效果。然而,在光通信过程中,光强分布的变化会导致光栅列阵中每个单元的响应度不一致,从而引起每个单元接收到的光信号出现差异,进而影响光束的整形效果。因此,提出一种考虑光强分布的光通信光栅列阵光束整形方法。以光通信光栅列阵中的最常用的列阵波导光栅为例,通过阵列波导结构中的阵列波导的芯区宽度、芯区折射率、包层折射率、波导周期宽度等参数,结合波导中的传播常数受到光束波长和折射率影响,得到阵列波导的归一化本征方程,将其结果结合匀化洛伦兹函数得到入射光和出射光的光强分布,通过计算得到光通信光栅列阵光束入射光及出射光的映射函数,利用函数调整光学参数,实现光通信光栅列阵光束整形。实验结果表明:该方法对光通信光栅列阵光束的整形效果好,整形光束的能量利用率高,光束不均匀性小。

微闪耀光栅列阵实现全混洗变换研究

在8台阶、相位深度为2π的微闪耀光栅透过率函数的基础上,根据标量衍射理论分析了波长0.6328μm的He-Ne激光通过闪耀光栅发生菲涅耳衍射的复振幅分布,并得到了其满足1级闪耀输出的特点.将He-Ne激光通过8通道的微闪耀光栅列阵后菲涅耳衍射光场的分布规律与全混洗变换的特点相结合,得到微闪耀光栅列阵实现全混洗变换的周期公式.实验表明该微闪耀光栅列阵能够实现全混洗变换.

紫外写入光纤布拉格光栅列阵的制备

我们将在光纤上写入Bragg光栅.所用写入激光器为KrF准分子激光器(Lambda Physik制造),波长为248 nm,每个脉中的能量密度为300 mJ/cm2,重复率为100 Hz;相位掩膜(加拿大制造)的面积为10 mm×5 mm,周期为1071 nm,曝光几分钟可得峰值反射率为99%带宽在0.12至0.4 nm的FEG.我们采用先给光纤施加适当应力,然后进行紫外曝光写入Bragg光栅.当去掉应力后,Bragg波长将向短波方向移动.用这种方法我们在单根3M光纤上写入5个光栅列阵,每个光栅的Bragg波长间隔为0.88 nm.原则上说,在光纤能承受的最大应力限度内,可写入光栅Bragg波长的最大跨度为8 nm.(OD15)

聚合物阵列波导光栅波分复用器的研究

利用甲基丙稀酸甲酯 -甲基丙稀酸缩水甘油酯共聚物制作聚合物光波导 ,对聚合物阵列波导光栅波分复用器的原理、版图设计及制作工艺进行了研究。设计了聚合物阵列波导光栅的版图 ,并利用厚胶掩模和铝掩模两种工艺完成了聚合物阵列波导光栅光波导的制作。实验结果证明 ,与厚胶掩模相比 ,铝掩模具有较好工艺重复性 ,同时也更能实现设计所要求的参数。

列阵波导光栅复用器及其应用

介绍用于波分复用的一种新型的无源器件列阵波导光栅 ,分析其工作原理 ,概述制备方法、用途和目前的发展状况 .

4×4列阵波导光栅复用器/解复用器理论设计

简要分析了列阵波导光栅复用器／解复用器的传播特性， 利用有效折射率法求解了ＳｉＯ２：ＧｅＯ２ 单模脊型掩埋通道波导的传播常数， 并在此基础上完成了４×４ 列阵波导光栅复用器／解复用器的理论设计和数值模拟分析， 这些结果对设计实用化器件有较大帮助。

Polymer/Si AWG器件材料光学性质的准确测量

使用WVASE32型椭偏仪,对Si基单层有机薄膜的测量方法进行分析;并对聚甲基丙烯酸甲酯(PMMA)材料和氟化聚酯材料进行测量,根据测量结果对阵列波导光栅(AWG)器件进行设计.在124nm到1700nm之间可测量出任意波长的折射率,其均方差(MSE)均远小于1,证明测量结果极其准确.同时探讨了对多层有机薄膜及氟化聚合物薄膜的测量方法.

Triplexers Based on SOI Flattop AWGs

Triplexers are designed based on SOl flattop arrayed waveguide gratings （AWGs）. Three wavelengths （1310, 1490,and 1550nm） operate at three diffraction orders of AWGs. Simulation shows that the 3dB bandwidth,crosstalk, and loss are 6nm,less than -40dB, and 5dB, respectively. The output optical fields of the device fabricated in our laboratory are clear and show a good triplexing function.

Polarization-Insensitive Silica on Silicon Arrayed Waveguide Grating Design

A new technology for fabrication of silica on silicon arrayed waveguide grating (AWG) based on deep etching and thermal oxidation is presented.Using this method,a silicon layer is remained at the side of waveguide.The stress distribution and effective refractive index of waveguide fabricated by this approach are calculated using finite element and finite difference beam propagation method,respectively.The results of these studies indicate that the stress of silica on silicon optical waveguide can be matched in parallel and vertical direction and AWG polarization dependent wavelength (PDλ) can be reduced effectively due to side-silicon layer.

A Novel Compact-Structure Arrayed-Waveguide Grating Device

Arrayed waveguide grating (AWG) device,a novel compact structure,is presented based on silicon on insulator (SOI) material.A total internal reflection (TIR) waveguide mirror is fabricated at the middle of each arrayed waveguide.An approach of compensating TE TM mode polarization is presented by using the phase difference,which is caused by TIR at the waveguide mirror.This AWG device has advantage for its small size and simple technigue of fabrication.The experimental results are given and the feasibility of fabrication is tested.

Design and fabrication of ultrasmall arrayed waveguide grating multiplexers based on Si nanowire waveguides

The large refractive index difference between Si and SiO2 makes it possible to realize ultrasmall photonic integrated circuits. A 5×5 ultracompact arrayed waveguide grating multiplexer based on 500×250 nm Si nanowire waveguides is designed and fabricated by using the technologies of E-beam writing and amorphous-Si deposition. The mea- sured channel spacing is about 1.5 nm (close to the design value) and the channel crosstalk is about –8 dB.

Invited Paper: The Audacity of Fiber-Wireless(FiWi) Networks: Revisited for Clouds and Cloudlets

There is a growing awareness among industry players of reaping the benefits of mobile-cloud convergence by extending today's unmodified cloud to a decentralized two-level cloud-cloudlet architecture based on emerging mobile-edge computing(MEC) capabilities. In light of future 5G mobile networks moving toward decentralization based on cloudlets, intelligent base stations, and MEC, the inherent distributed processing and storage capabilities of radio-and-fiber(R&F) networks may be exploited for new applications, e.g., cognitive assistance, augmented reality, or cloud robotics. In this paper, we first revisit fiber-wireless(Fi Wi) networks in the context of conventional clouds and emerging cloudlets, thereby highlighting the limitations of conventional radio-overfiber(Ro F) networks such as China Mobile's centralized cloud radio access network(C-RAN) to meet the aforementioned trends. Furthermore, we pay close attention to the specific design challenges of data center networks and revisit our switchless arrayedwaveguide grating(AWG) based network with efficient support of east-west flows and enhanced scalability.

Analysis of Optical Signal Transmission Characteristics in AWG Multi/Demultiplexer with Electromagnetic Field Theory

Based on the electromagnetic field theory, the optical signal transmission characteristics in input/output waveguides, slab waveguides and arrayed waveguides of the arrayed waveguide grating (AWG) multi/demultiplexer are analyzed. The relationship between the physical parameters such as geometry sizes and relative refractive index in AWG multi/demultiplexer and the optical signal transmission characteristics are discussed. This theoretical study can be used for optimizing the design and improving the performance of the AWG multi/demultiplexer.

Influence of Crosstalk on Signal Power Based on Arrayed-waveguide Grating as N × N Optical Router

The fact that the signal results in signal―crosstalk is confirmed forarrayed―waveguide grating as NXN optical router, and the relation between the crosstalk and powerpenalty is obtained. The method reveals the random distributions of optical path phase errors in twomultiplexers with channel numbers of 10 and 160. It is shown that the crosstalk must be less than―28 dB for a power penalty below 1 dB at a bit error rate of 1X10^(-9). It is found that when N =100, crosstalk power value is ? 20 dB with compensation power of 2―3 dB, so the compensation poweris not ignored.

The Optical Emission Spectroscopy Experiment of Open Air Plasmas

A plasma spectroscopy experiment is described and its performances are given, ways oI excltauon u^ttc~,t tc~,,,,,~ ,,, free-burning plasma at atmospheric pressure is analyzed in detail. The fixed-grating spectrograph PGS-2 Carl Zeiss Jena is actually a variation on the very first spectrometer design, where photo-plate was replaced with a detector array of PIXIS-Roper Scientific camera. Abilities of the system are analyzed and its limitations are determined.

Review of the Low-Latency Optical Interconnect Technologies for Peta-Scale Computing

This paper reviews the recently developed optical interconnect technologies designed for scalable, low latency and high-throughput comunications within datacenters or high perforrmnce computers. The three typical architectures including the broadcast-and-select based Optical Shared Memory Supercomputer Interconnect System （OSMOSIS） switch, the defection routing based Data Vortex switch and the arrayed waveguide grating based Low-latency Interconnect Optical Network Switch （LIONS） switch are discussed in detail. In particular, we investigate the various Ioopback buffering technologies in LIONS and present a proof of principle testbed demonstration showing feasibility of LIONS architecture. Moreover, the performance of LIONS, Data Vortex and OSMOSIS with traditional state-of-the-art electrical switching network based on the Flattened-ButterFly （FBF） architecture in terms of throughput and latency are compared. The sinmlation based perfortmnce study shows that the latency of LIONS is almost independent of the number of input ports and does not saturate even at very high input load.

AWG用Si基SiO_2波导材料的制备

平面光波导在光波分复用技术中起着重要的作用 ,尤其是 Si基 Si O2 波导器件在光通信领域中具有许多优点。因此 ,如何在 Si衬底上制备出性能稳定良好的 Si O2 光波导材料至关重要。本文介绍了几种制备 Si O2

Polymer Arrayed Waveguide Grating with Box-Like Spectral Response

An efficient technique is used to flatten the spectral response of an arrayed waveguide grating （AWG） multiplexer. By subtracting an increment from the core width of odd arrayed waveguides and by adding the same increment to that of even arrayed waveguides,a box-like spectral response can be obtained. A 17 × 17 polymer AWG multiplexer with box- like spectral response has been made using FPE polymer materials. Measured result for the AWG shows that the box-like spectral response has a 3dB bandwidth of 0. 476nm, the crosstalk is about or less than - 21dB for every output channel,and the insertion loss is 13-15dB.

Quasi-Dammann grating with proportional intensity of array spots for surface hardening of metal

For surface hardening of metal,a quasi-Dammann grating (QDG) is proposed and fabricated to generate array spots with proportional-intensity distribution.To get uniformly hardened band distribution and improve the wear resistance of the sample surface,a three-order QDG is designed to produce array spots with enhanced intensity in the edge.The design and fabrication of the QDG are described in detail.The surface profile of the fabricated grating was measured,which shows that the fabrication error is less than 2%.The laser beam intensity distribution shaped by the QDG was tested by a laser beam analyzer to verify the validity of the QDG.The application of the QDG in the laser surface hardening of metal was experimentally investigated,and the results show that the hardness distribution of the modified layer and the wear resistance of the sample surface are improved significantly by using the QDG.

Design and fabrication of 25-channel 200 GHz AWG based on Si nanowire waveguides

A 25-channel 200 GHz arrayed waveguide grating （AWG） based on Si nanowire wavegnides is designed, simulated and fab- ricated. Transfer function method is used in the simulation and error analysis of AWG with width fluctuations. The 25-channel 200 GHz AWG exhibits central channel insertion loss of 6.7 dB, crosstalk of-13 dB, and central wavelength of 1 560.55 nm. The error analysis can explain the experimental results of 25-channel 200 GHz AWG well. By using deep ul- traviolet lithography （DUV） and inductively coupled plasma etching （ICP） technologies, the devices are fabricated on sili- con-on-insulator （SOI） substrate.