检索结果-南通市图书馆

维普期刊数据库

Lithium niobate microring with ultra-high q factor above 10～8

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2022年第1期20卷 122-126页

作者：高仁宏姚妮管江林邓莉林锦添汪旻乔玲玲方伟程亚 State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-Intense Laser Science Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences (CAS) Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Research Center for Intelligent Sensing Zhejiang Lab XXL—The Extreme Optoelectromechanics Laboratory School of Physics and Electronic Science East China Normal University State Key Laboratory of Precision Spectroscopy East China Normal University State Key Laboratory of Modern Optical Instrumentation College of Optical Science and Engineering Zhejiang University Collaborative Innovation Center of Extreme Optics Shanxi University Collaborative Innovation Center of Light Manipulations and Applications Shandong Normal University Shanghai Research Center for quantum Sciences

We demonstrate integrated lithium niobate(LN) microring resonators with q factors close to the intrinsic material absorption limit of *** microrings are fabricated on pristine LN thin-film wafers thinned from LN bulk via chemo-mechanical etching without ion slicing and ion etching.A record-high q factor up to 10～8 at the wavelength of 1550 nm is achieved because of the ultra-smooth interface of the microrings and the absence of ion-induced lattice damage,indicating an ultra-low waveguide propagation loss of ～0.0034 dB/*** ultra-high q microrings will pave the way for integrated quantum light source,frequency comb generation,and nonlinear optical processes.

关键词： Chemical vapor deposition Femtosecond laser writing Frequency combs Lithium niobate q factor quantum light sources

Tomographic inversion of near-surface q factor by combining surface and cross-hole seismic surveys

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Applied Geophysics 2016年第1期13卷 93-102,219,220页

作者：李国发郑浩祝文亮王明超翟桐立中国石油大学(北京)油气资源与探测国家重点实验室北京102249 中国石油天然气股份有限公司大港油田分公司天津300280

The estimation of the quality factor q plays a fundamental role in enhancing seismic resolution via absorption compensation in the near-surface *** present a new geometry that can be used to acquire field data by combining surface and cross-hole surveys to decrease the effect of geophone coupling on q *** this study,we drilled number of receiver holes around the source hole,each hole has different depth and each geophone is placed geophones into the bottom of each receiver hole to avoid the effect of geophone coupling with the borehole wall on q estimation in conventional cross-hole seismic *** also propose a novel tomographic inversion of the q factor without the effect of the source signature,and examine its stability and reliability using synthetic *** estimate the q factors of the near-surface layer in two different frequency bands using field data acquired in the Dagang *** results show that seismic absorption in the nearsurface layer is much greater than that in the subsurface ***,it is of critical practical importance to enhance the seismic solution by compensating for near-surface *** addition,we derive different q factors from two frequency bands,which can be treated,to some extent,as evidence of a frequency-dependent q.

关键词： near surface q factor tomographic inversion spectral ratio method frequency dependence

维普期刊数据库

Abnormal enhancement to the quality factors of carbon nanotube via defects engineering

在线全文

学校读者我要写书评

暂无评论

Nano Materials Science 2022年第3期4卷 259-265页

作者： Ke Duan Li Li Sihan Liu Yujin Hu Xuelin Wang State Key Lab of Digital Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China

Low quality(q) factor is often the limiting factor for high performance carbon nanotube(CNT) resonators. The most commonly used approach to enhance the q factor of CNTs is to reduce/eliminate the intrinsic ***, we show surprisingly that hole defects of suitable size and position are able to enhance the q factor of CNT, which strongly contradicts to the common notion that the presence of defects promote intrinsic dissipation via defects dissipation. By analyzing the strain distribution, we find that such abnormal enhancement in q factor of defected CNT originates from a coupling competition mechanism between the atomic mismatch around defected atoms and the thermoelastic damping. Although the presence of holes will introduce an additional defect dissipation source, suitable holes are capable of reducing the energy dissipation arisen from the thermoelastic damping, through changing the spatial strain field of defected CNT. This coupling competition mechanism provides a new route for designing high performance CNT resonators via defects engineering.

关键词： Defects engineering CNT resonator q factor

维普期刊数据库

Plasmon-induced transparency in terahertz metamaterials

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2013年第12期56卷 73-90页

作者： JING HuiHui ZHU ZhiHua ZHANG Xueqian GU Jianqiang TIAN Zhen OUYANG ChunMei HAN JiaGuang ZHANG WeiLi Center for Terahertz waves and College of Precision Instrument and Optoelectronics Engineering Tianjin University and the Key Laboratory of Optoelectronics Information Technology (Ministry of Education) School of Electrical and Computer Engineering Oklahoma State University

The quantum phenomena of electromagnetically induced transparency(EIT)or plasmonic analogue of electromagnetically induced transparency(PIT)can be mimicked in the classical resonators,leading to a unique way to explore the coherent coupling mechanism in metamaterial *** metamaterial structures have been proposed to excite and manipulate the PIT efect with flexibility and performance with geometry-controllable,polarization-independent,broadband-transparency and active-modulated *** in turn promise the fascinating functionalities and applications of the PIT efects,such as slow-light components,nonlinear devices and high-sensitivity ***,we present a review on the progress in developing the PIT efect in terahertz metamaterials over the past few years.

关键词： PIT terahertz metamaterial q factor plasmon coupling

Mn0.8Zn0.2Fe2O4 nanoparticulates spinel ferrites:An approach to enhance the antenna field strength for improved magnitude versus offset(MVO)

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2014年第4期24卷 364-372页

作者： Majid Niaz Akhtar Nadeem Nasir Muhammad Kashif Noorhana Yahya Mukhtar Ahmad Ghulam Murtaza Muhammad Azhar Khan M.H.Asif A.Sattar R.Raza M.Saleem S.N.Khan Department of Physics COMSATS Institute of Information Technology Electrical and Electronic Engineering Department Universiti Teknologi PETRONAS Fundamental and Applied Sciences Department National Textile University Fundamental and Applied Sciences Department Universiti Teknologi PETRONAS Centre for Advanced Studies in Physics G.C.University Department of Physics The Islamia University of Bahawalpur

Electromagnetic signals in deep reservoir are very weak so that it is difficult to predict about the presence of hydrocarbon in seabed logging(SBL) *** the present work,Mn0.8Zn0.2Fe2O4 nanoferrites were prepared by a sol–gel technique at different sintering temperatures of450 °C,650 °C and 850 °C to increase the strength of electromagnetic(EM) ***,FESEM,Raman spectroscopy and HRTEM were used to analyze the phase,surface morphology and size of the *** properties of the nanoferrites were also measured using an impedance network ***,nanoferrites sintered at 850 °C with initial permeability of 200 and q factor of 50 were used as magnetic feeders with the EM *** scale experiments were performed to investigate the effect of magnetic field strength in scale *** and MATLAB softwares were also used to confirm the oil presence in scale *** was observed that the magnitude of the EM waves for the antenna was increased up to 233%.Finally,the correlation values also show 208% increase in the magnetic field strength with the presence of the ***,antenna with Mn0.8Zn0.2Fe2O4 nanoferrites based magnetic feeders can be used for deep water and deep target hydrocarbon exploration.

关键词： Nanoferrites Transmission Electron Microscopy Initial permeability q factor Antenna

Microring resonator for glucose sensing applications

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Optoelectronics 2009年第3期2卷 304-307页

作者： Yao CHEN Zhengyu LI Huaxiang YI Zhiping ZHOU Jun YU Department of Electronic Science and Technology Huazhong University of Science and Technology Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology State Key Laboratory on Advanced Optical Communication Systems and Networks Peking University School of Electrical and Computer Engineering Georgia Institute of Technology

Silicon nitride microring resonators were demonstrated as chemical sensors. The microring devices,with diameter of 100 μm, were fabricated using complementary metal oxide semiconductor（CMOS）-compatible technology, and a high q factor of 15000 was realized with free spectrum range（FSR） of 2 nm. The structures were further packaged to perform as chemical sensors, and their functionality was proved using deionized water（DI water）and ethanol as detecting mediums. Lastly, the packaged chips were used to detect glucose solutions with various concentrations, and a detection capability of refractive index change of 10–3refractive index unit（RIU） was obtained.

关键词： microring resonator chemical sensor glucose sensing refractive index unit (RIU) q factor

Measuring Crustal Lg-Waves Attenuation in the Northern Part of Africa

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Earthquake Research 2016年第2期5卷 105-113页

作者： Adoum Issak Christian Camerlynck Faculté des Sciences Exactes et Appliquées N’Djamena Tchad Sorbonne Universités UPMC Univ Paris 6 Paris France

Lg-waves propagate over long distances in the northern part of Africa and are recorded on the seismic station located close to Abeche (Chad). We have applied the well-known coda analysis method developed by Aki and Chouet [1] to study the Lg-wave anelastic attenuation in this area. We found a frequency dependence: q( f ) = (650±34) f (0.77±0.2). This result shows an average value of q0 (q0 ≈ 650) for earthquakes occurred in tectonic areas as the East African Rift system, Turkey, Greece and Red Sea. The higher value of q0 (q0 ≈ 800) is obtained for the event occurred in the middle of the stable plate close to the Tamanrasset (TAM) station in Algeria.

关键词： Lg-Wave Attenuation Coda q factor North Africa

Research on Dispersion Compensation of 40 GB/s Optical Duo-Binary Coded Transmission System

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Optics and Photonics Journal 2016年第8期6卷 190-195页

作者： Yue Zhou Yufeng Shao Zhifeng Wang Changxiang Li Junyi Zhou Wenzhe Ma Faculty of Engineering Shanghai Polytechnic University Shanghai China

A 40 Gb/s high speed optical transmission system is designed, and the different dispersion compensation schemes are adopted to realize the transmission of the optical duo-binary (ODB) signals over 120 km optical fiber. Optical duo-binary signals are generated by using a precoder, two low- pass filters (LPF) and one mach-zehnder modulator (MZM). Through combination of dispersion compensation fiber (DCF) and single mode fiber (SMF) in the transmission link, four different dispersion compensation schemes (pre-compensation, post-compensation and hybrid compensation (pre+ post) and hybrid compensation (post+ pre)) were compared. Analyzing q factor, BER, eye diagrams and receiver sensitivity in several dispersion compensation schemes, the simulation results are: the cut-off frequency of LPF affects the transmission performance, and the hybrid compensation (post+ pre) scheme is the optimal dispersion compensation method.

关键词： Optical Communication Duo-Binary Dispersion Compensation q factor Eye Diagrams

Modeling and Analysis of Penalty on Optical Signal Performance Duo to Low-Frequency Subcarriers Multiplexing

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Modeling and Analysis of Penalty on Optical Signal Performan...