Advances in Optical Technologies最新文献_第5页

Low-Frequency Raman Spectroscopic Monitoring of Supramolecular Structure in H-Bonded Liquids 氢键液体超分子结构的低频拉曼光谱监测

Advances in Optical Technologies Pub Date : 2014-03-04 DOI: 10.1155/2014/798632

N. Kuzkova, A. Yakunov, M. U. Bilyi

引用次数: 4

Optical Response to Submicron Digital Elements Simulated by FDTD Wavelets with Refractive Impulse 带折射脉冲的FDTD小波模拟亚微米数字元件的光学响应

Advances in Optical Technologies Pub Date : 2014-03-04 DOI: 10.1155/2014/682614

A. Bourdillon

引用次数: 0

Polarization Division Multiplexing of OFDM Radio-over-Fiber Signals in Passive Optical Networks 无源光网络中OFDM光纤上无线电信号的极化分复用

Advances in Optical Technologies Pub Date : 2014-02-27 DOI: 10.1155/2014/269524

M. Morant, Joaquin Perez, R. Llorente

{"title":"Polarization Division Multiplexing of OFDM Radio-over-Fiber Signals in Passive Optical Networks","authors":"M. Morant, Joaquin Perez, R. Llorente","doi":"10.1155/2014/269524","DOIUrl":"https://doi.org/10.1155/2014/269524","url":null,"abstract":"This paper describes the state-of-the-art of polarization multiplexing for optical networks transmission. The use of polarization division multiplexing (PDM) permits to multiply the user capacity and increase the spectral efficiency. Combining PDM and orthogonal frequency division multiplexed (OFDM) modulation allows maximizing the optical transmission capacity. The experimental demonstration of transmitting OFDM signals following ECMA-368 ultrawide band (UWB) standard in radio-over-fiber using PDM in passive optical networks is herein reported. The impact of cross-polarization and cochannel crosstalk is evaluated experimentally in a three-user OFDM-UWB subcarrier multiplexed (SCM) configuration per polarization. Each SCM uses up to three OFDM-UWB channels of 200 Mbit/s each, achieving an aggregated bitrate of 1.2 Gbit/s with 0.76 bit/s/Hz spectral efficiency when using PDM transmission. The experimental results for the polarization-multiplexed SCM indicate that a 4 dB additional polarization crosstalk interference can be expected compared to a nonpolarization-multiplexed transmission system which translates to 2.4 dB EVM penalty in the UWB signals. The successful PDM transmission of SCM multiuser OFDM-UWB over a passive optical network of 25 km standard-single mode fiber (SSMF) reach is demonstrated.","PeriodicalId":156432,"journal":{"name":"Advances in Optical Technologies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130009450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 25

Total Internal Reflection-Based High Efficiency Grating Design for a Metal-Free Polarizing Filter Applications Using Hybrid Optimization Procedure 基于全内反射的无金属偏振滤波器高效光栅设计应用于混合优化程序

Advances in Optical Technologies Pub Date : 2014-02-10 DOI: 10.1155/2014/393010

Chabum Lee

{"title":"Total Internal Reflection-Based High Efficiency Grating Design for a Metal-Free Polarizing Filter Applications Using Hybrid Optimization Procedure","authors":"Chabum Lee","doi":"10.1155/2014/393010","DOIUrl":"https://doi.org/10.1155/2014/393010","url":null,"abstract":"This paper presents a fast and rigorous design method for grating-based metal-free polarizing filter applications using two-step hybrid optimization techniques. Grating structures utilizing the total internal reflection in a lamellar configuration were used to achieve metal-free solution, which is a key technology in the chirped pulse amplification for high power laser system. Here two polarizing filters were designed: polarization sensitive and polarization insensitive. Those polarization performances were characterized by the rigorous coupled-wave analysis (RCWA), and the design parameters of grating structures, pitch, depth, and filling factor were optimized by two-step hybrid optimization procedure because the diffraction characteristics of grating-based polarizing filters are highly sensitive to small changes in design parameters. The Taguchi method is incorporated into selection process in the genetic algorithm, which indicates that the Taguchi method optimizes the design parameters in a coarse manner, and then, coarsely optimized parameters are finely optimized using the genetic algorithm. Therefore the proposed method could solve global numerical optimization problems with continuous variables. The proposed two-step hybrid optimization algorithm could effectively optimize the grating structures for the purpose of polarization filter applications, and the optimized grating structures could selectively filter the incident light up to 99.8% as to TE or TM waves.","PeriodicalId":156432,"journal":{"name":"Advances in Optical Technologies","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132184200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Application of the G'/G Expansion Method in Ultrashort Pulses in Nonlinear Optical Fibers G′/G展开法在非线性光纤超短脉冲中的应用

Advances in Optical Technologies Pub Date : 2013-12-11 DOI: 10.1155/2013/636472

Jiang Xing-fang, Wang Jun, Wei Jianping, Hua Ping

引用次数: 6

Neural Network Modeling for Prediction of Weld Bead Geometry in Laser Microwelding 激光微焊接焊缝几何形状预测的神经网络建模

Advances in Optical Technologies Pub Date : 2013-12-09 DOI: 10.1155/2013/415837

M. Ismail, Y. Okamoto, A. Okada

{"title":"Neural Network Modeling for Prediction of Weld Bead Geometry in Laser Microwelding","authors":"M. Ismail, Y. Okamoto, A. Okada","doi":"10.1155/2013/415837","DOIUrl":"https://doi.org/10.1155/2013/415837","url":null,"abstract":"Laser microwelding has been an essential tool with a reputation of rapidity and precision for joining miniaturized metal parts. In industrial applications, an accurate prediction of weld bead geometry is required in automation systems to enhance productivity of laser microwelding. The present work was conducted to establish an intelligent algorithm to build a simplified relationship between process parameters and weld bead geometry that can be easily used to predict the weld bead geometry with a wide range of process parameters through an artificial neural network (ANN) in laser microwelding of thin steel sheet. The backpropagation with the Levenberg-Marquardt training algorithm was used to train the neural network model. The accuracy of neural network model has been tested by comparing the simulated data with actual data from the laser microwelding experiments. The predictions of the neural network model showed excellent agreement with the experimental results, indicating that the neural network model is a viable means for predicting weld bead geometry. Furthermore, a comparison was made between the neural network and mathematical model. It was found that the developed neural network model has better prediction capability compared to the regression analysis model.","PeriodicalId":156432,"journal":{"name":"Advances in Optical Technologies","volume":"18 772 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131124314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 31

Photonic Processing for Wideband Cancellation and Spectral Discrimination of RF Signals 射频信号宽带对消与频谱识别的光子处理

Advances in Optical Technologies Pub Date : 2013-12-05 DOI: 10.1155/2013/738427

D. Benton

引用次数: 1

Minimizing the Bright/Shadow Focal Spot Size with Controlled Side-Lobe Increase in High-Numerical-Aperture Focusing Systems 最大限度地减少明亮/阴影焦点光斑尺寸与控制副瓣增加在高数值孔径聚焦系统

Advances in Optical Technologies Pub Date : 2013-11-20 DOI: 10.1155/2013/267684

S. Khonina, S. G. Volotovskiy

引用次数: 7

Modeling and Simulation of Piecewise Regular Multimode Fiber Links Operating in a Few-Mode Regime 分段规则多模光纤链路在少模状态下的建模与仿真

Advances in Optical Technologies Pub Date : 2013-11-12 DOI: 10.1155/2013/469389

A. Bourdine

引用次数: 29

Automatic Characterization of the Visual Appearance of Industrial Materials through Colour and Texture Analysis: An Overview of Methods and Applications 通过颜色和纹理分析自动表征工业材料的视觉外观:方法和应用综述

Advances in Optical Technologies Pub Date : 2013-10-30 DOI: 10.1155/2013/503541

E. González, F. Bianconi, M. Álvarez, S. Saetta

引用次数: 16