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Novel method for measurement of effective cavity length of DBR fiber

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Chinese Optics Letters 2010年第4期8卷 398-400页

作者：冀青马秀荣孙静张昊姚颖 School of Computer and communication Engineering tianjin university of technology Engineering Research Center of Communication DevicesMinistry of Education tianjin key laboratory of film electronic and communication devices Tianjin University of Technology Institute of Modern Optics Nankai university

A novel method to measure the effective cavity length of distributed Bragg reflector（DBR） fiber laser with fiber Bragg grating（FBG） Fabry-Perot cavity as the resonator is *** effective cavity length of DBR fiber laser is accurately measured by measuring the frequency spacing of two adjacent longitudinal modes in the cavity without the precise physical length of *** measuring accuracy as high as 10^（-5） mm can be obtained by setting the resolution bandwidth of the spectrum analyzer.

关键词： Fiber Bragg gratings Fiber lasers Fibers Spectrum analyzers

Synthesis of nanostructural ZnO using hydrothermal method for dye-sensitized solar cells

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Science china(Technological Sciences) 2010年第4期53卷 1146-1149页

作者： WANG ChunXiao1,2,ZHANG XiaoDan1,WANG DongFeng1,YANG ZhenHua1,2,JI WeiWei1,ZHANG CunShan2 & ZHAO Ying1 1 Institute of Photo-electronic Thin film devices and technology of Nankai university,key laboratory of Photo-electronic Information Science and technology(Nankai university),Ministry of Education,tianjin 300071,china 2 College of Information Engineering,Hebei university of technology,tianjin 300130,china 1. key laboratory of Photo-electronic Information Science and technology (Nankai university) Ministry of Education Institute of Photo-electronic Thin Film Devices and Technology of Nankai University Tianjin 300071 China2. College of Information Engineering Hebei University of Technology Tianjin 300130 China

ZnO nanocrystals with different morphologies were successful synthesized by a simple hydrothermal method combined with and without hexadecyl trimethyl ammonium bromide(CTAB).The phases and morphologies of the products were measured using X-ray diffraction(XRD),scanning electron microscopy(SEM),and transmission electron microscopy(TEM),*** results indicated that the ZnO nanocrystals with different morphologies were of hexagonal wurtzite *** nanorods were obtained without using CTAB,and then the morphology of ZnO changed to ZnO nanoflower and the density of nanoflower became denser with the increase of CTAB *** nanoflower and ZnO nanorod as photoanode were applied to dye-sensitized solar cells(DSSC),*** nanoflower shows a higher dye loading,so DSSC with the use of the ZnO nanoflower possesses a higher conversion efficiency than ZnO nanorod.

关键词： DSSC ZnO

THz source based on optical Cherenkov radiation

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Science china(Information Sciences) 2012年第1期55卷 27-34页

作者： YAO JianQuan1,2,LIU PengXiang1,2,XU DeGang1,2,LV YingJin1,2&LV Da1,2 1Institute of Laser&Optoelectronics,College of Precision Instruments and Opto-electronic Engineering,tianjin university,tianjin 300072,china 2key laboratory of Opto-electronics Information technology(tianjin university),Ministry of Education,tianjin 300072,china 1. Institute of Laser & Optoelectronics College of Precision Instruments and Opto-Electronic Engineering Tianjin University Tianjin 300072 China2. Ministry of Education Key Laboratory of Opto-electronics Information Technology (Tianjin University) Tianjin 300072 China

Terahertz(THz)technique has attracted considerable interest due to its broad application *** source is a crucial part of THz science and *** Cherenkov radiation in electro-optic crystals is a promising method of THz generation,because phase-matching is automatically *** this paper,we introduced two types of THz source based on optical Cherenkov radiation:both broadband and tunable *** mechanism of radiation was analyzed and recent development was reviewed in *** future of THz source based on optical Cherenkov radiation was also forecasted.

关键词： Terahertz source optical rectification dierence frequency generation Cherenkov radiation

Compact High-performance Bulk Optical Isolator

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Chinese Journal of Lasers 1998年第2期B7卷 31-36页

作者： WANG Lindou(Department of electronic Engineering,tianjin university,tianjin 300072,china) tianjin Univ Tianjin China

ＣｏｍｐａｃｔＨｉｇｈ┐ｐｅｒｆｏｒｍａｎｃｅＢｕｌｋＯｐｔｉｃａｌＩｓｏｌａｔｏｒＷＡＮＧＬｉｎｄｏｕ（ＤｅｐａｒｔｍｅｎｔｏｆＥｌｅｃｔｒｏｎｉｃＥｎｇｉｎｅｅｒｉｎｇ，ＴｉａｎｊｉｎＵｎｉｖｅｒｓｉｔｙ，Ｔｉａ... 详细信息

ＣｏｍｐａｃｔＨｉｇｈ┐ｐｅｒｆｏｒｍａｎｃｅＢｕｌｋＯｐｔｉｃａｌＩｓｏｌａｔｏｒＷＡＮＧＬｉｎｄｏｕ（ＤｅｐａｒｔｍｅｎｔｏｆＥｌｅｃｔｒｏｎｉｃＥｎｇｉｎｅｅｒｉｎｇ，ＴｉａｎｊｉｎＵｎｉｖｅｒｓｉｔｙ，Ｔｉａｎｊｉｎ３０００７２，Ｃｈｉｎａ）...

关键词： isolaton fiber optic communication bulk isolator

A new kind of superimposing morphology for enhancing the light scattering in thin film silicon solar cells： Combining random and periodic structure

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Chinese Physics B 2014年第8期23卷 350-356页

作者： Huang Zhen-Hua Institute of Photo-electronics Thin film devices and Technique of Nankai university Tianjin 300071 China key laboratory of Photo-electronics Thin film devices and Technique of tianjin Tianjin 300071 China key laboratory of Photo-electronic Information Science and technology of Ministry of Education (Nankai university) Tianjin 300071 China

In this article, a new type of superimposing morphology comprised of a periodic nanostructure and a random structure is proposed for the first time to enhance the light scattering in silicon-based thin film solar cells. According to the framework of the Reyleigh-Sommerfeld diffraction algorithm and the experimental results of random morphologies, we analyze the light-scattering properties of four superimposing morphologies and compare them with the individual morphologies in detail. The results indicate that the superimposing morphology can offer a better light trapping capacity, owing to the coexistence of the random scattering mechanism and the periodic scattering mechanism. Its scattering property will be dominated by the individual nanostructures whose geometrical features play the leading role.

关键词： light scattering superimposing morphology random periodic

First-principles calculations on implanted TiO_2 by 3d transition metal ions

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Science china(Physics,Mechanics & Astronomy) 2009年第6期52卷 838-842页

作者： HOU XingGang1,2, HUANG MeiDong1, WU XiaoLing2 & LIU AnDong2 1 Department of Physics, tianjin Normal university, tianjin 300387, china 2 key laboratory of Beam technology and Material Modification of Ministry of Education, Beijing Normal university, Beijing 100875, china Department of Physics Tianjin Normal University Tianjin 300387 China key laboratory of Beam technology and Material Modification of Ministry of Education Beijing Normal University Beijing 100875 China

3d transition metal (V, Cr and Fe) ions are implanted into TiO2 by the method of metal ion implantation. The electronic band structures of TiO2 films doped 3d transition metal ions have been analyzed by ab initio band calculations based on a self-consistent full-potential linearized augmented plane-wave method within the first-principle formalism. Influence of implantation on TiO2 films is examined by the method of UV-visible spectrometry. The results of experiment and calculation show that the optical band gap of TiO2 films is narrowed by ion implantation. The calculation shows that the 3d state of V, Cr and Fe ions plays a significant role in red shift of UV-Vis absorbance spectrum.

关键词： 3d transition metal ions implantation TiO2 FP-LAPW electronic structure

Sintering characteristics and microstructure of WC-Co-VC/Cr_3C_2 ultrafine cemented carbides

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Rare Metals 2009年第5期28卷 482-486页

作者： LEI Yiwen WU Enxi School of Mechanical and electronic Engineering Tianjin Polytechnic University Tianjin 300160 China State key laboratory of Powder Metallurgy Central South University Changsha 410083 China

The sintering characteristics, microstructure, and mechanical properties of ultrafine WC-12%Co-0.2%VC/0.5%Cr3C2 cemented carbides were investigated. Dilatometric and differential thermal analyses （DTA） indicate that the compacts start to shrink at 600°C, the shrinkage rate peak is at 1190°C, and the liquid formation temperature is lower than the W-C-Co eutectic temperature （1330°C）. Microstructure analysis results show that the cemented carbides with fine and homogeneous microstructure were obtained when sintered at 1430°C. Continuous and discontinuous grain growth was suppressed due to the synergistic action of VC/Cr3C2. The transverse rupture strength （TRS） of the samples reaches 4286 MPa, with the hardness HRA 92.1. The fine and homogeneous microstructure, alloy strengthening, and different phase constitutions of binder in the cemented carbides result in high hardness and TRS. Continuous and discontinuous grain growth was observed in the cemented carbide sintered at 1450°C, which results in significant decreases of hardness and TRS. It indicates that VC/Cr3C2 additions in the cemented carbides can only suppress the grain growth at a certain temperature.

关键词： cemented carbides sintering characteristic grain growth microstructure mechanical properties

Effects of femtosecond laser ablation on the surface morphology and microstructure of a bulk TiCuPdZr glass alloy

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Rare Metals 2009年第3期28卷 272-276页

作者： WANG Hongshui LIANG Chunyong CHEN Xueguang WANG Lei YANG Yang YANG Jianjun ZHU Shengli LI Changyi School of Materials Science and Engineering Hebei University of Technology Tianjin 300130 China key laboratory of the Ministry of Education of china for Opto-electronic Information Science and technology Institute of Modem Optics Nankai University Tianjin 300071 China School of Materials Science and Engineering Tianjin University Tianjin 300072 China Stomatological Hospital Tianjin Medical University Tianjin 300070 China

The effects of femtosecond laser ablation on the surface characteristics and microstructure of a bulk TiCuPdZr glass alloy were investigated. The heat influence zone of femtosecond laser ablated with a laser energy of 100 μJ exhibits a ripple-like feather, while a porous structure appears on the surface of the specimen ablated by a 200 μJ femtosecond laser. The contents of Ti, Zr, and Pd on the ablated surface decrease and that of Cu increases with increasing laser energy. The crystallization process occurs on the glass alloy specimens during femtosecond laser ablation, and the crystallinity of a 100 μJ femtosecond laser-ablated specimen is greater than that of a 200 μJ femtosecond laser-ablated one.

关键词： femtosecond laser bulk glass alloy periodicity crystallization

Control of Pinhole Defects Formation in Semi-flexible Coaxial Cable by Vertical Tin-Plating Process

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Transactions of tianjin university 2011年第5期17卷 320-323页

作者：程方杰肖鑫孙贵铮杨立军张凤玉 School of Materials Science and Engineering Tianjin University tianjin key laboratory of Advanced Joining technology tianjin Anxunda Ltd

Holistic tin-plating on the outer conductor is one of the key processes in the manufacture of semi-flexible coaxial cable, which is widely applied to the third generation (3G) mobile communication system. However, in the traditional horizontal tin-plating process, disadvantages such as the pinhole defects and low productivity effect cannot be avoided. In this paper, a vertical tin-plating process was proposed to reduce the pinhole defects and improve the tincoating quality. Compared with the traditional horizontal tin-plating process, the immersion length was reduced from 300-400 mm to 10-100 mm and the tin-plating time was reduced from 7 s to 3 s in the proposed method. The experimental results indicate that immersion length and time are key parameters for the tin-plating quality. With this new tin-plating process, the experimental results show that the pinhole defects can be eliminated effectively by controlling the immersion depth below 100 mm and tin-plating time at 3 s. The thickness of tin-coating increased from not more than 5 μm to 12.3 μm with the proposed vertical tin-plating process. Meanwhile, the thickness of the intermetallic compounds (IMCs) layer between the tin-coating and copper wires was reduced from 3.26 μm to 0.62 μm if the immersion time decreased from 30 s to 1 s. Besides, a self-developed flux, which possesses a boiling point or decomposed temperature of active components over 300℃, exhibits a better efficiency in reducing the pinhole formation.

关键词： 3G communication network semi-flexible coaxial cable vertical tin-plating pinhole defect