检索结果-南通市图书馆

On-chip integrated few-mode erbium–ytterbium co-doped waveguide amplifiers

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2024年第5期12卷 1067-1077页

作者： XIWEN HE deyue ma CHEN ZHOU MINGYUE XIAO WEIBIAO CHEN ZHIPING ZHOU Aerospace Laser Technology and Systems Department Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Center of materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China School of Physical Sciences University of Science and Technology of ChinaHefei 230026China School of Microelectronics Shanghai UniversityShanghai 201800China State Key Laboratory of Advanced Optical Communications Systems and Networks School of ElectronicsPeking UniversityBeijing 100871China

We propose for the first time,to the best of our knowledge,an on-chip integrated few-mode erbium–ytterbium co-doped waveguide amplifier based on an 800 nm thick Si_(3)N_(4)platform,which demonstrates high amplification gains and low differential modal gains(DMGs)*** eccentric waveguide structure and a co-propagating pumping scheme are adopted to balance the gain of each mode.A hybrid mode/polarization/wavelengthdivision(de)multiplexer with low insertion loss and crosstalk is used for multiplexing and demultiplexing in two operation wavebands centered at 1550 nm and 980 nm,where the light in these two bands serves as the signal light and pump light of the amplifier,*** results demonstrate that with an input signal power of 0.1 mW,TE_(0)mode pump power of 300 mW,and TE_(1)mode pump power of 500 m W,the three signal modes(TE_(0)∕TM_(0)∕TE_(1))all exhibit amplification gains exceeding 30 dB,while maintaining a DMG of less than 0.1 dB.

关键词： waveguide pump amplifier

Design of an on‑chip wavelength conversion device assisted by an erbium‑ytterbium co‑doped waveguide amplifier

在线全文

学校读者我要写书评

暂无评论

Frontiers of Optoelectronics 2024年第2期17卷 51-60页

作者： Chen Zhou Xiwen He Mingyue Xiao deyue ma Weibiao Chen Zhiping Zhou School of Physical Sciences University of Science and Technology of ChinaHefei 230026China Aerospace Laser Technology and System Department Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Hangzhou Aijie Optoelectronic Technology Co.Ltd. Hangzhou 311400China

In current documented studies,it has been observed that wavelength converters utilizing AlGaAsOI waveguides exhibit suboptimal on-chip wavelength conversion efficiency from the C-band to the 2μm band,generally falling below−20.0 *** address this issue,we present a novel wavelength conversion device assisted by a waveguide amplifier,incorporating both AlGaAs wavelength converter and erbium-ytterbium co-doped waveguide amplifier,thereby achieving a notable conversion efficiency exceeding 0 *** noteworthy enhancement in efficiency can be attributed to the specific dispersion design of the AlGaAs wavelength converter,which enables an upsurge in conversion efficiency to−15.54 dB under 100 mW of pump ***,the integration of an erbium-ytterbium co-doped waveguide amplifier facilitates a loss compensation of over 15 *** the use of external optical amplifiers,this device enables efficient and high-bandwidth wavelength conversion,showing promising applications in various fields,such as optical communication,sensing,imaging,and beyond.

关键词： Silicon-based optoelectronics Wavelength conversion Waveguide amplifier 2μm band

石墨烯/铜镍铁氧体复合材料的制备及性能研究

在线全文

学校读者我要写书评

暂无评论

红外与激光工程 2018年第9期47卷 221-226页

作者：马德跃李晓霞郭宇翔曾宇润国防科技大学脉冲功率激光技术国家重点实验室安徽合肥230037 安徽省红外与低温等离子体重点实验室安徽合肥230037

为制备出宽波段磁波衰减材料,采用水热法制备得到了石墨烯/铜镍铁氧体复合材料(CNFRGO),并对其进行SEM、XRD、红外光谱和拉曼光谱表征分析;然后测量其2~18 GHz的电磁参数,并计算其损耗角正切值和反射损耗,进而分析其微波衰减性能;最后,... 详细信息

为制备出宽波段磁波衰减材料,采用水热法制备得到了石墨烯/铜镍铁氧体复合材料(CNFRGO),并对其进行SEM、XRD、红外光谱和拉曼光谱表征分析;然后测量其2~18 GHz的电磁参数,并计算其损耗角正切值和反射损耗,进而分析其微波衰减性能;最后,测量其中远红外波段的复折射率,利用测量数据和T矩阵法计算分析其红外波段消光和吸收性能。结果表明,尖晶石型铜镍铁氧体纳米颗粒吸附在还原石墨烯上,粒径大部分约为20 nm;CNFRGO同时具有介电损耗和磁损耗两种机制,其反射损耗低于-10 d B的频宽为3.7 GHz,在11.8 GHz处有峰值-14.7 d B;CNFRGO在近红外波段消光较强主要由散射引起,中远红外波段则主要由吸收决定,而其吸收能力在近红外和中红外波段较强,但在远红外大气窗口内相对较弱。因此,CNFRGO可同时吸收微波和红外辐射,是一种良好的微波与红外兼容材料。

关键词：石墨烯铜镍铁氧体水热法电磁参数复折射率

在线全文

学校读者我要写书评

暂无评论

先驱体成型对膨胀石墨激光消光性能的影响

红外与激光工程 2016年第1期45卷 200-204页

作者：马德跃李晓霞郭宇翔赵亮赵纪金脉冲功率激光技术国家重点实验室(电子工程学院) 安徽合肥230037 北京遥感信息研究所北京100192

可膨胀石墨是制备膨胀石墨（EG）的先躯体,压柱成型会对其膨胀所得EG的激光消光性能产生影响。为了优化其成型参数,将先驱体可膨胀石墨（GIC）采用不同压强压制成药柱,对其热膨胀特性及膨胀后所得EG的膨胀体积（EV）、蠕虫形貌、微观结... 详细信息

可膨胀石墨是制备膨胀石墨（EG）的先躯体,压柱成型会对其膨胀所得EG的激光消光性能产生影响。为了优化其成型参数,将先驱体可膨胀石墨（GIC）采用不同压强压制成药柱,对其热膨胀特性及膨胀后所得EG的膨胀体积（EV）、蠕虫形貌、微观结构以及对1.064μm激光的消光性能展开了研究。结果表明：相较于松散态,成型GIC先驱体所制备的EG蠕虫变细、变短,孔隙率降低;成型压强由0 MPa增至50 MPa,其EV由356 ml/g减小到216 ml/g,所得EG对1.064μm激光的质量消光截面σM由0.18 m2/g减小到0.04 m2/g,且在20~40 MPa时EV变化率仅为10.6%,σM变化率同样很小。显然,存在对EV及σM影响较小的压强范围,因此,在EG工程应用中,为满足尽可能大的装药密度,GIC成型可考虑选该压强范围的上限值。

关键词：可膨胀石墨膨胀石墨膨胀体积消光性能

在线全文

学校读者我要写书评

暂无评论

长航时UAV蒙皮红外辐射强度的工程计算

红外与激光工程 2017年第3期46卷 46-52页

作者：黄章斌李晓霞郭宇翔马德跃赵亮电子工程学院脉冲功率激光技术国家重点实验室安徽合肥230037 安徽省红外与低温等离子体重点实验室安徽合肥230037

无人机(Unmanned Aerial Vehicle,UAV)蒙皮的红外辐射特性是对UAV进行探测识别的重要依据,而UAV蒙皮的气动力加热、太阳辐射换热、地球辐射换热等是影响UAV蒙皮辐射特性的主要因素。在综合考虑了环境以及UAV自身辐射的情况下,建立了UAV... 详细信息

无人机(Unmanned Aerial Vehicle,UAV)蒙皮的红外辐射特性是对UAV进行探测识别的重要依据,而UAV蒙皮的气动力加热、太阳辐射换热、地球辐射换热等是影响UAV蒙皮辐射特性的主要因素。在综合考虑了环境以及UAV自身辐射的情况下,建立了UAV蒙皮红外辐射的计算模型,采用向前差分法求出了UAV蒙皮的一维导热微分方程,并在此基础上,结合UAV蒙皮材料的发射率,计算了在某一平面上UAV红外辐射强度的分布情况。计算结果表明:蒙皮在8~14μm波段处红外辐射强度远大于3~5μm波段的红外辐射强度;相同波段处,蒙皮正上方的辐射强度大于正下方的辐射强度。

关键词：无人机环境辐射蒙皮温度发射率红外辐射强度

在线全文

学校读者我要写书评

暂无评论

红外烟幕遮蔽率及其分布表征方法

应用光学 2014年第4期35卷 707-712页

作者：马德跃李晓霞郭宇翔赵纪金电子工程学院脉冲功率激光技术国家重点实验室安徽合肥230037 电子工程学院红外与低温等离子体安徽省重点实验室安徽合肥230037

目标与背景的辐射对比度是红外系统探测目标的主要依据,也是烟幕干扰重点降低的一个参量。结合辐射对比度的定义和红外定标原理,由目标和背景的视在辐射亮度引入其视在辐射对比度,并与目标和背景热像图的灰度值关联起来。利用烟幕遮蔽... 详细信息

目标与背景的辐射对比度是红外系统探测目标的主要依据,也是烟幕干扰重点降低的一个参量。结合辐射对比度的定义和红外定标原理,由目标和背景的视在辐射亮度引入其视在辐射对比度,并与目标和背景热像图的灰度值关联起来。利用烟幕遮蔽前后与目标和背景视在辐射对比度变化相对应的热像灰度对比度的变化,对烟幕遮蔽率进行表征。用提出的背景灰度方法对干扰实验结果进行了表征,计算得到3组试验的背景灰度值分别为91.902 4、88.002 0、33.285 6,并获得了目标区域各像元遮蔽率的直观分布图,克服了以往以点代面的评价方法。

关键词：辐射定标辐射对比度红外烟幕遮蔽率

A FINITE ELEMENT METHOD WITH PERFECTLY maTCHED ABSORBING LAYERS FOR THE WAVE SCATTERING BY A PERIODIC CHIRAL STRUCTURE

在线全文

学校读者我要写书评

暂无评论

Journal of Computational mathematics 2007年第4期25卷 458-472页

作者： deyue Zhang Fuming ma School of mathematics Jilin University Changchun 130012 China School of Computer Science and Technology Jilin University Changchun 130012 China School of mathematics Jilin University Changchun 130012 China

Consider the diffraction of a time-harmonic wave incident upon a periodic chiral structure. The diffraction problem may be simplified to a two-dimensional one. In this paper, the diffraction problem is solved by a finite element method with perfectly matched absorbing layers （PMLs）. We use the PML technique to truncate the unbounded domain to a bounded one which attenuates the outgoing waves in the PML region. Our computational experiments indicate that the proposed method with complicated chiral grating structures. is efficient, which is capable of dealing

关键词： Chiral media Perfectly matched layer Grating optics.

Local magnetic moment oscillation around an Anderson impurity on graphene

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 192-201页

作者： Shuai Li Zhen ma Jin-Hua Gao School of Science Hebei University of Science and Technology School of Electronics and Information Zhengzhou University of Light Industry School of Physics and Wuhan National High magnetic Field Center Huazhong University of Science and Technology

We theoretically investigate the spin resolved Friedel oscillation （FO） and quasiparticle interference （QPI） in graphene induced by an Anderson *** the impurity becomes magnetic,the resulted FO becomes spin dependent,which gives rise to a local magnetic moment oscillation with an envelop decaying as r-2in real space in the doping ***,at half filling,the electron density and local magnetic moment will not oscillate but decay as *** spin resolved FO has both sublattice and spin ***,the local magnetic moment decay at half filling only occurs at one sublattice of graphene,which is quite like the phenomenon observed in the STM experiment (***ález-Herrero et al.,Science 352,437 （2016）).We further give an analytic formula about such spin dependent FO based on the stationary phase ***,we study the interference of quasiparticles around the magnetic impurity by calculating the spin dependent Fourier-transformed local density of states （FT-LDOS）.Our work gives a comprehensive understanding about the local magnetic moment oscillation around an Anderson impurity on graphene.

关键词： Friedel oscillation local magnetic moment graphene Anderson impurity

Harnessing therapeutic potential of induced pluripotent stem cell–derived endothelial cells for remyelination in the central nervous system

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第6期20卷 1715-1716页

作者： Dan ma Nona Pop Aston Medical School College of Health and Life SciencesAston UniversityBirminghamUK

Myelin is the protective sheath surrounding nerve fibers, and its damage(demyelination) occurs in many central nervous system(CNS) diseases, including multiple sclerosis(MS), traumatic injury, neurodegenerative diseases such as Alzheimer's disease, and mental disorders such as schizophrenia(Barateiro et al., 2016). Repair of damaged myelin sheaths(remyelination) often fails in MS, leading to neuronal loss and irreversible functional deficits.

关键词： myelin protective diseases