检索结果-内蒙古大学图书馆

Asia Communications and Photonics Conference, ACPC 2015

作者： Sun, Jian Tan, Zhongwei Li, Tangjun Wang, Muguang Institute of Lightwave Technology Key Lab of All Optical Network and Advanced Telecommunication Network China

ISBN: (纸本)9781943580064

We propose and demostrate a novel all-optical correlator based on modal dispersion in multimode fiber. The incident optical signal is copied into different modes in a large core high numerical aperture step-index multimode fiber and time delay is introduced by modal dispersion. We use a mask with slits as a space filter to select the modes needed. A correlator of the mask and input signal is achieved at the output end. Thanks to the use of modal dispersion, the correlator is nearly independent of the wavelength and bandwidth of input signal. By adjusting slits on the mask, the target patterns of the correlator can be changed easily. © 2015 OSA.

关键词： Multimode fibers

来源：评论

学校读者我要写书评

暂无评论

Stable single-polarization single-longitudinal-mode linear cavity erbium-doped fiber laser based on structured chirped fiber Bragg grating

Stable single-polarization single-longitudinal-mode linear c...

引用

作者： Yin, Bin Liu, Zhibo Feng, Suchun Bai, Yunlong Li, Haisu Jian, Shuisheng Institute of Lightwave Technology Key Lab of All Optical Network and Advanced Telecommunication of EMC Beijing Jiaotong University Beijing China

A novel linear cavity erbium-doped fiber (EDF) laser based on a structured chirped fiber Bragg grating (CFBG) filter is proposed for stable single-polarization (SP) single-longitudinal-mode (SLM) operation. For the first time, to the best of our knowledge, a structured CFBG filter with an ultranarrow transmission band which is generated by tapering directly on CFBG is used to select the laser longitudinal mode. The SLM operation is obtained by using the structured CFBG together with an unpumped EDFacting as a saturable absorber. The fluctuations of the laser peak power and center wavelength are less than 0.07 dB and 1 pm in 1 h, respectively. The stable SP operation is achieved by using the inline broadband polarizer. The measured 20 dB laser linewidth is about 27.7 kHz, which indicates the laser linewidth is approximately 1.39 kHz FWHM. © 2014 optical Society of America.

关键词： Saturable absorbers

来源：评论

学校读者我要写书评

暂无评论

Single polarization and poling optimized twin-hole optical fiber

引用

Chinese Optics Letters 2015年第13期13卷 12-14页

作者：黄琳任国斌 Key Lab of All Optical Network & Advanced Telecommunication Network of EMC Beijing Jiaoton~ University Beijin~ 100044 China Institute of Lightwave Technology Beijing Jiaotong University Beijing 100044 China

We investigate optimal twin-hole poling optical fiber configurations, including distances between core and each electrode, and poling voltage based on the two-dimensional charge dynamics model. We propose a poled fiber with optimized x^（2） as well as single-polarization property. Small distance between core and anode guarantees the poled fiber with large x^（2） in fiber core and large polarization-dependent loss. A maximum x^（2） in the core region either outside or inside nonlinear layer can be realized by appropriately selecting edge-to-edge distance between core and cathode. The maximum x^（2） in the core region can be even larger by increasing the poling voltage.

关键词： 060.4370 Nonlinear optics, fibers 060.2430 Fibers, single-mode 060.2280 Fiber design and fabrication

来源：评论

学校读者我要写书评

暂无评论

Wideband RCS reduction of slot antenna array by using reflectarrays 6

Wideband RCS reduction of slot antenna array by using reflec...

引用

6th IEEE International Symposium on Microwave, Antenna, Propagation, and emc Technologies, MAPE 2015

作者： Han, Yunhao Chen, Meie Wang, Junhong Zhan, Zhang Zheng, Li Key Lab of All Optical Network Advanced Telecommunication Network of MOE Beijing Jiaotong University Beijing China 1nstitute of Lightwave Technology Beijing Jiaotong University Beijing China

ISBN: (纸本)9781467374415

According to the principle of reflectarray, this paper presents a new way which disperses the scattered energy into different directions to reduce the RCS of the slot antenna array, preserving its radiating performance at the same time. Four reflectarrays are designed using double square ring elements of variable size, and they are loaded onto the patch side of the slot antenna array by region. The reflectarrays disperse the scattering field into different directions, which makes a significant reduction of monostatic RCS in a wide frequency band including in-band and out-band. The backward RCS of the slot antenna array with reflectarrays can be reduced as much as 20dBsm compared to that of the conventional antenna array. © 2015 IEEE.

关键词： Antenna arrays

来源：评论

学校读者我要写书评

暂无评论

Spectral analysis of the UFBG-based acousto optical modulator in V–I transmission matrix formalism

引用

Chinese Physics B 2014年第11期23卷 251-256页

作者：吴良英裴丽刘超王一群翁思俊王建帅 Key Laboratory of All Optical Network & Advanced Telecommunication Network of EMC Beijing Jiaotong Univcnersity

In this study, the V –I transmission matrix formalism(V –I method) is proposed to analyze the spectrum characteristics of the uniform fiber Bragg grating(FBG)-based acousto–optic modulators(UFBG-AOM). The simulation results demonstrate that both the amplitude of the acoustically induced strain and the frequency of the acoustic wave(AW) have an effect on the spectrum. Additionally, the wavelength spacing between the primary reflectivity peak and the secondary reflectivity peak is proportional to the acoustic frequency with the ratio 0.1425 nm/MHz. Meanwhile, we compare the amount of calculation. For the FBG whose period is M, the calculation of the V –I method is 4 ×(2M-1) in addition/subtraction,8 ×(2M- 1) in multiply/division and 2M in exponent arithmetic, which is almost a quarter of the multi-film method and transfer matrix(TM) method. The detailed analysis indicates that, compared with the conventional multi-film method and transfer matrix(TM) method, the V –I method is faster and less complex.

关键词： uniform fiber bragg grating(UFBG) acousto–optic modulator(AOM) V–I transmission matrix formalism spectrum

来源：评论

学校读者我要写书评

暂无评论

Coherent near-mid-IR supercontinuum generation in highly nonlinear multi-cladding liquid-coe fiber designed for flat normal dispersion

Coherent near-mid-IR supercontinuum generation in highly non...

引用

European Conference on Lasers and Electro-Optics, CLEO 2015

作者： Wang, C.C. Bache, M. Technical University of Denmark Department of Photonics Engineering Kgs. LyngbyDK-2800 Denmark Key Lab of All Optical Network and Advanced Telecommunication Network of EMC Beijing Jiaotong University Beijing100044 China Institute of Lightwave Technology Beijing Jiaotong University Beijing100044 China

来源：评论

学校读者我要写书评

暂无评论

A Root-Locus Design Methodology Derived from the Impedance Stability Criterion and Its Application for LCL Grid-Connected Converters

A Root-Locus Design Methodology Derived from the Impedance S...

引用

European Conference on Power Electronics and Applications

作者： Enrique Rodriguez-Diaz Francisco D. Freijedo Mohammad S. Golsorkhi Juan C. Vasquez Josep M. Guerrero Key Laboratory of All Optical Network and Advanced Telecommunication Network of EMC Institute of Lightwave Technology Beijing Jiaotong University Beijing China Faculty of Sciences and Technology São Paulo State University Sao Paulo Brazil Department of Geodesy Federal University of Rio Grande do Sul Porto Alegre RS Brazil Faculty of Sciences and Technology Sao Paulo State University Sao Paulo Brazil Univ. Grenoble Alpes ISTerre France

ISBN: (纸本)9781509014101

This paper presents a systematic methodology for design and tuning of the controller of LCL grid-connected converters. The proposed approach is derived from the impedance/admittance stability formulation, which eases the controller modelling of LCL grid-connected systems. After system modelling, a modified sensitivity function is defined to analyze the closed loop dynamics. For practical development, the control objectives are linked to main requirements in wind turbine applications: 1) the current control time constant should be minimized and 2) active damping actions should effectively mitigate the LCL resonance. After the theoretical development, an insightful case study is provided. It is shown that the tuning problem can be solved approximately by root-loci inspection and an optimum solution can be found by direct search. The theoretical approach is experimentally verified by a lab-scale prototype that uses the same parameters of the case study.

关键词： Ac/dc converter Active damping Converter control Wind energy

来源：评论

学校读者我要写书评

暂无评论

Investigation on the intensity noise characteristics of the semiconductor ring laser

引用

Chinese Physics B 2014年第2期23卷 262-269页

作者：康泽新蔡鑫伦温晓东刘超简水生余思远 Key Laboratory of All Optical Network & Advanced Telecommunication Network of EMC Institute of Lightwave TechnologyBeijing Jiaotong University The Department of Electrical and Electronic Engineering University of Bristol

Based on the frequency-domain multimode theoretical model, detailed investigations on the noise characteristic of the semiconductor ring laser （SRL） are first performed in this paper. The comprehensive nonlinear terms related to the third order nonlinear susceptibility Z3 are included in this model; the Langevin noise sources for electric field and carrier density fluctuations are also taken into account. As the injection current increases, the SRL may present several operation regimes. Remarkable and unusual low frequency noise enhancement in the form of a broad low frequency tail extending all the way to the relaxation oscillation peak is observed in any of the operation regimes of SRLs. The influences of the backscattering coefficient on the relative intensity noise （RIN） spectrum in typical operation regimes are investigated in detail.

关键词： semiconductor ring laser relative intensity noise low frequency noise enhancement

来源：评论

学校读者我要写书评

暂无评论

Wideband RCS Reduction of Slot Antenna Array by Using Reflectarrays

Wideband RCS Reduction of Slot Antenna Array by Using Reflec...

引用

The 6th International Symposium on Microwave,Antenna,Propagation,and Electromagnetic Compatibility Technologies(MAPE 2015)

作者： Yunhao Han Meie Chen Junhong Wang Zhan Zhang Zheng Li Key Lab of All Optical Network & Advanced Telecommunication Network of MOE Beijing Jiaotong University Institute of Lightwave Technology Beijing Jiaotong University

According to the principle of reflectarray, this paper presents a new way which disperses the scattered energy into different directions to reduce the RCS of the slot antenna array, preserving its radiating performance at the same time. Four reflectarrays are designed using double square ring elements of variable size, and they are loaded onto the patch side of the slot antenna array by region. The reflectarrays disperse the scattering field into different directions, which makes a significant reduction of monostatic RCS in a wide frequency band including in-band and out-band. The backward RCS of the slot antenna array with reflectarrays can be reduced as much as 20 d Bsm compared to that of the conventional antenna array.

关键词： reflectarray slot antenna array RCS reduction

来源：评论

学校读者我要写书评

暂无评论

A cost-effective ultra-dense WDM PON system with speed of 12.5 Gbit/s and channel spacing of 12.5 GHz

引用

Optoelectronics Letters 2014年第6期10卷 455-458页

作者：牟宏谦王目光简水生 Key Laboratory of All Optical Network and Advanced Telecommunication Network of EMC Institute of Lightwave TechnologyBeijing Jiaotong University

A cost-effective ultra-dense wavelength-division-multiplexed passive optical network(UD-WDM PON) with speed of 12.5 Gbit/s and channel spacing of 12.5 GHz is proposed and demonstrated. The distributed feedback(DFB) lasers modulated in 4-level pulse amplitude modulation(4-PAM) format are used for downstream links, and the reflective semiconductor optical amplifiers(RSOAs) together with an optical frequency comb modulated in quadrature phase shift keying(QPSK) format are used for upstream links. We can achieve the error-free transmission of the upstream signals with speed of 12.5 Gbit/s even after 20 km single-mode fiber(SMF). The power penalty obtained by using the frequency comb generator instead of a tunable laser is around 0.5 d B. By using 11 DFB lasers and a set of intensity and phase modulators, it is possible to provide the seed light for 297 optical network units(ONUs) within the C-band.

关键词： Amplitude modulation Cost effectiveness Dense wavelength division multiplexing Distributed feedback lasers Feedback Light amplifiers optical systems Phase shift Phase shifters Pulse amplitude modulation Quadrature phase shift keying Semiconductor optical amplifiers Single mode fibers

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：