共 50 条
- [1] Fundamental characteristics and high-speed applications of carrier-depletion silicon Mach-Zehnder modulatorsIEICE ELECTRONICS EXPRESS, 2014, 11 (24):Ogawa, Kensuke论文数: 0 引用数: 0 h-index: 0机构: Fujikura Ltd, Opt & Elect Lab, Sakura, Chiba 285855, Japan Fujikura Ltd, Opt & Elect Lab, Sakura, Chiba 285855, JapanIshihara, Hiroki论文数: 0 引用数: 0 h-index: 0机构: Fujikura Ltd, Opt & Elect Lab, Sakura, Chiba 285855, Japan Fujikura Ltd, Opt & Elect Lab, Sakura, Chiba 285855, JapanGoi, Kazukiro论文数: 0 引用数: 0 h-index: 0机构: Fujikura Ltd, Opt & Elect Lab, Sakura, Chiba 285855, Japan Fujikura Ltd, Opt & Elect Lab, Sakura, Chiba 285855, JapanMashiko, Yasuhiro论文数: 0 引用数: 0 h-index: 0机构: Fujikura Ltd, Opt & Elect Lab, Sakura, Chiba 285855, Japan Fujikura Ltd, Opt & Elect Lab, Sakura, Chiba 285855, JapanLim, Soon Thor论文数: 0 引用数: 0 h-index: 0机构: ASTAR, Inst High Performance Comp, Singapore 138632, Singapore Fujikura Ltd, Opt & Elect Lab, Sakura, Chiba 285855, JapanSun, Min Jie论文数: 0 引用数: 0 h-index: 0机构: Optic2Connect Pte Ltd, Singapore 139951, Singapore Fujikura Ltd, Opt & Elect Lab, Sakura, Chiba 285855, JapanSeah, Sean论文数: 0 引用数: 0 h-index: 0机构: Optic2Connect Pte Ltd, Singapore 139951, Singapore Fujikura Ltd, Opt & Elect Lab, Sakura, Chiba 285855, JapanPng, Ching Eng论文数: 0 引用数: 0 h-index: 0机构: ASTAR, Inst High Performance Comp, Singapore 138632, Singapore Fujikura Ltd, Opt & Elect Lab, Sakura, Chiba 285855, JapanLiow, Tsung-Yang论文数: 0 引用数: 0 h-index: 0机构: ASTAR, Inst Microelect, Singapore 117685, Singapore Fujikura Ltd, Opt & Elect Lab, Sakura, Chiba 285855, JapanTu, Xiaoguang论文数: 0 引用数: 0 h-index: 0机构: ASTAR, Inst Microelect, Singapore 117685, Singapore Fujikura Ltd, Opt & Elect Lab, Sakura, Chiba 285855, JapanLo, Guo-Qiang论文数: 0 引用数: 0 h-index: 0机构: ASTAR, Inst Microelect, Singapore 117685, Singapore Fujikura Ltd, Opt & Elect Lab, Sakura, Chiba 285855, JapanKwong, Dim-Lee论文数: 0 引用数: 0 h-index: 0机构: ASTAR, Inst Microelect, Singapore 117685, Singapore Fujikura Ltd, Opt & Elect Lab, Sakura, Chiba 285855, Japan
- [2] Chirp Characteristics of Silicon Mach-Zehnder ModulatorsOPTOELECTRONIC MATERIALS AND DEVICES V, 2011, 7987Wei, Yuxin论文数: 0 引用数: 0 h-index: 0机构: Zhejiang Univ, Dept Informat Sci & Elect Engn, Hangzhou 310027, Zhejiang, Peoples R China Zhejiang Univ, Dept Informat Sci & Elect Engn, Hangzhou 310027, Zhejiang, Peoples R ChinaZhao, Yong论文数: 0 引用数: 0 h-index: 0机构: Zhejiang Univ, Dept Informat Sci & Elect Engn, Hangzhou 310027, Zhejiang, Peoples R China Zhejiang Univ, Dept Informat Sci & Elect Engn, Hangzhou 310027, Zhejiang, Peoples R ChinaLi, Guoyi论文数: 0 引用数: 0 h-index: 0机构: Zhejiang Univ, Dept Informat Sci & Elect Engn, Hangzhou 310027, Zhejiang, Peoples R China Zhejiang Univ, Dept Informat Sci & Elect Engn, Hangzhou 310027, Zhejiang, Peoples R ChinaYang, Jianyi论文数: 0 引用数: 0 h-index: 0机构: Zhejiang Univ, Dept Informat Sci & Elect Engn, Hangzhou 310027, Zhejiang, Peoples R China Zhejiang Univ, Dept Informat Sci & Elect Engn, Hangzhou 310027, Zhejiang, Peoples R ChinaWang, Minghua论文数: 0 引用数: 0 h-index: 0机构: Zhejiang Univ, Dept Informat Sci & Elect Engn, Hangzhou 310027, Zhejiang, Peoples R China Zhejiang Univ, Dept Informat Sci & Elect Engn, Hangzhou 310027, Zhejiang, Peoples R ChinaJiang, Xiaoqing论文数: 0 引用数: 0 h-index: 0机构: Zhejiang Univ, Dept Informat Sci & Elect Engn, Hangzhou 310027, Zhejiang, Peoples R China Zhejiang Univ, Dept Informat Sci & Elect Engn, Hangzhou 310027, Zhejiang, Peoples R China
- [3] High-speed InP-Based Mach-Zehnder modulators for telecom applications2005 IEEE CSIC SYMPOSIUM, TECHNICAL DIGEST, 2005, : 25 - 28Yasaka, H论文数: 0 引用数: 0 h-index: 0机构: NTT Corp, NTT Photon Labs, Atsugi, Kanagawa 2430198, Japan NTT Corp, NTT Photon Labs, Atsugi, Kanagawa 2430198, JapanTsuzuki, K论文数: 0 引用数: 0 h-index: 0机构: NTT Corp, NTT Photon Labs, Atsugi, Kanagawa 2430198, Japan NTT Corp, NTT Photon Labs, Atsugi, Kanagawa 2430198, JapanKikuchi, N论文数: 0 引用数: 0 h-index: 0机构: NTT Corp, NTT Photon Labs, Atsugi, Kanagawa 2430198, Japan NTT Corp, NTT Photon Labs, Atsugi, Kanagawa 2430198, JapanYamada, E论文数: 0 引用数: 0 h-index: 0机构: NTT Corp, NTT Photon Labs, Atsugi, Kanagawa 2430198, Japan NTT Corp, NTT Photon Labs, Atsugi, Kanagawa 2430198, JapanShibata, Y论文数: 0 引用数: 0 h-index: 0机构: NTT Corp, NTT Photon Labs, Atsugi, Kanagawa 2430198, Japan NTT Corp, NTT Photon Labs, Atsugi, Kanagawa 2430198, JapanIshibashi, T论文数: 0 引用数: 0 h-index: 0机构: NTT Corp, NTT Photon Labs, Atsugi, Kanagawa 2430198, Japan NTT Corp, NTT Photon Labs, Atsugi, Kanagawa 2430198, Japan
- [4] Analysis of Optical and Electrical Tradeoffs of Traveling-Wave Depletion-Type Si Mach-Zehnder Modulators for High-Speed OperationIEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, 2015, 21 (04) : 199 - 206Petousi, Despoina论文数: 0 引用数: 0 h-index: 0机构: IHP, D-15236 Frankfurt, Oder, Germany IHP, D-15236 Frankfurt, Oder, GermanyZimmermann, Lars论文数: 0 引用数: 0 h-index: 0机构: IHP, D-15236 Frankfurt, Oder, Germany IHP, D-15236 Frankfurt, Oder, GermanyGajda, Andrzej论文数: 0 引用数: 0 h-index: 0机构: Tech Univ Berlin, Fachgebiet Hochfrequenztech, D-10587 Berlin, Germany IHP, D-15236 Frankfurt, Oder, GermanyKroh, Marcel论文数: 0 引用数: 0 h-index: 0机构: IHP, D-15236 Frankfurt, Oder, Germany IHP, D-15236 Frankfurt, Oder, GermanyVoigt, Karsten论文数: 0 引用数: 0 h-index: 0机构: Tech Univ Berlin, Fachgebiet Hochfrequenztech, D-10587 Berlin, Germany IHP, D-15236 Frankfurt, Oder, GermanyWinzer, Georg论文数: 0 引用数: 0 h-index: 0机构: IHP, D-15236 Frankfurt, Oder, Germany IHP, D-15236 Frankfurt, Oder, GermanyTillack, Bernd论文数: 0 引用数: 0 h-index: 0机构: IHP, D-15236 Frankfurt, Oder, Germany IHP, D-15236 Frankfurt, Oder, GermanyPetermann, Klaus论文数: 0 引用数: 0 h-index: 0机构: Tech Univ Berlin, Fachgebiet Hochfrequenztech, D-10587 Berlin, Germany IHP, D-15236 Frankfurt, Oder, Germany
- [5] MACH-ZEHNDER QUANTUM WELL MODULATORS FOR AEROSPACE APPLICATIONS2008 IEEE AVIONICS, FIBER-OPTICS AND PHOTONICS TECHNOLOGY CONFERENCE, 2008, : 57 - 58Kunkee, Elizabeth论文数: 0 引用数: 0 h-index: 0机构: Northrop Grumman Space Technol, Manhattan Beach, CA 90278 USA Northrop Grumman Space Technol, Manhattan Beach, CA 90278 USADavis, Richard论文数: 0 引用数: 0 h-index: 0机构: Northrop Grumman Space Technol, Manhattan Beach, CA 90278 USA Northrop Grumman Space Technol, Manhattan Beach, CA 90278 USASmith, Andrew D.论文数: 0 引用数: 0 h-index: 0机构: Northrop Grumman Space Technol, Manhattan Beach, CA 90278 USA Northrop Grumman Space Technol, Manhattan Beach, CA 90278 USA
- [6] High-Performance Hybrid Silicon and Lithium Niobate Mach-Zehnder Modulators2019 ASIA COMMUNICATIONS AND PHOTONICS CONFERENCE (ACP), 2019,He, Mingbo论文数: 0 引用数: 0 h-index: 0机构: Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, Sch Elect & Informat Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R ChinaXu, Mengyue论文数: 0 引用数: 0 h-index: 0机构: Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, Sch Elect & Informat Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R ChinaRen, Yuxuan论文数: 0 引用数: 0 h-index: 0机构: South China Normal Univ, Ctr Opt & Electromagnet Res, Guangdong Prov Key Lab Opt Informat Mat & Technol, Higher Educ Mega Ctr,South China Acad Adv Optoele, Sci Bldg 5, Guangzhou 510006, Peoples R China Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R ChinaJian, Jian论文数: 0 引用数: 0 h-index: 0机构: Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, Sch Elect & Informat Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R ChinaRuan, Ziliang论文数: 0 引用数: 0 h-index: 0机构: South China Normal Univ, Ctr Opt & Electromagnet Res, Guangdong Prov Key Lab Opt Informat Mat & Technol, Higher Educ Mega Ctr,South China Acad Adv Optoele, Sci Bldg 5, Guangzhou 510006, Peoples R China Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R ChinaXu, Yongsheng论文数: 0 引用数: 0 h-index: 0机构: South China Normal Univ, Ctr Opt & Electromagnet Res, Guangdong Prov Key Lab Opt Informat Mat & Technol, Higher Educ Mega Ctr,South China Acad Adv Optoele, Sci Bldg 5, Guangzhou 510006, Peoples R China Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R ChinaGao, Shengqian论文数: 0 引用数: 0 h-index: 0机构: Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, Sch Elect & Informat Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R ChinaSun, Shihao论文数: 0 引用数: 0 h-index: 0机构: Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, Sch Elect & Informat Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R ChinaWen, Xueqin论文数: 0 引用数: 0 h-index: 0机构: South China Normal Univ, Ctr Opt & Electromagnet Res, Guangdong Prov Key Lab Opt Informat Mat & Technol, Higher Educ Mega Ctr,South China Acad Adv Optoele, Sci Bldg 5, Guangzhou 510006, Peoples R China Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R ChinaZhou, Lidan论文数: 0 引用数: 0 h-index: 0机构: Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, Sch Elect & Informat Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R ChinaLiu, Lin论文数: 0 引用数: 0 h-index: 0机构: Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, Sch Elect & Informat Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R ChinaGuo, Changjian论文数: 0 引用数: 0 h-index: 0机构: South China Normal Univ, Ctr Opt & Electromagnet Res, Guangdong Prov Key Lab Opt Informat Mat & Technol, Higher Educ Mega Ctr,South China Acad Adv Optoele, Sci Bldg 5, Guangzhou 510006, Peoples R China Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R ChinaChen, Hui论文数: 0 引用数: 0 h-index: 0机构: Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, Sch Elect & Informat Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R ChinaYu, Siyuan论文数: 0 引用数: 0 h-index: 0机构: Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, Sch Elect & Informat Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R ChinaLiu, Liu论文数: 0 引用数: 0 h-index: 0机构: South China Normal Univ, Ctr Opt & Electromagnet Res, Guangdong Prov Key Lab Opt Informat Mat & Technol, Higher Educ Mega Ctr,South China Acad Adv Optoele, Sci Bldg 5, Guangzhou 510006, Peoples R China Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R ChinaCai, Xinlun论文数: 0 引用数: 0 h-index: 0机构: Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, Sch Elect & Informat Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R China
- [7] High-performance hybrid silicon and lithium niobate Mach-Zehnder modulators2020 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATIONS (ECOC), 2020,Cai, Xinlun论文数: 0 引用数: 0 h-index: 0机构: Sun Yat Sen Univ, Sch Elect & Informat Technol, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R China Sun Yat Sen Univ, Sch Elect & Informat Technol, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Peoples R China
- [8] Demonstration and Characterization of High-Speed Silicon Depletion-Mode Mach-Zehnder ModulatorsIEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, 2014, 20 (04)Xu, Hao论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 100083, Peoples R China Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 100083, Peoples R ChinaLi, Xianyao论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 100083, Peoples R China Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 100083, Peoples R ChinaXiao, Xi论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 100083, Peoples R China Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 100083, Peoples R ChinaLi, Zhiyong论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 100083, Peoples R China Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 100083, Peoples R ChinaYu, Yude论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 100083, Peoples R China Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 100083, Peoples R ChinaYu, Jinzhong论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 100083, Peoples R China Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 100083, Peoples R China
- [9] Compatibility of Silicon Mach-Zehnder Modulators for Advanced Modulation FormatsJOURNAL OF LIGHTWAVE TECHNOLOGY, 2013, 31 (15) : 2550 - 2554Xu, Ke论文数: 0 引用数: 0 h-index: 0机构: Chinese Univ Hong Kong, Dept Elect Engn, Shatin, Hong Kong, Peoples R China Chinese Univ Hong Kong, Dept Elect Engn, Shatin, Hong Kong, Peoples R ChinaYang, Ling-Gang论文数: 0 引用数: 0 h-index: 0机构: Natl Chiao Tung Univ, Dept Photon, Hsinchu 30010, Taiwan Chinese Univ Hong Kong, Dept Elect Engn, Shatin, Hong Kong, Peoples R ChinaSung, Jiun-Yu论文数: 0 引用数: 0 h-index: 0机构: Natl Chiao Tung Univ, Dept Photon, Hsinchu 30010, Taiwan Chinese Univ Hong Kong, Dept Elect Engn, Shatin, Hong Kong, Peoples R ChinaChen, Yimin M.论文数: 0 引用数: 0 h-index: 0机构: Chinese Univ Hong Kong, Dept Elect Engn, Shatin, Hong Kong, Peoples R China Chinese Univ Hong Kong, Dept Elect Engn, Shatin, Hong Kong, Peoples R ChinaCheng, Zhenzhou Z.论文数: 0 引用数: 0 h-index: 0机构: Chinese Univ Hong Kong, Dept Elect Engn, Shatin, Hong Kong, Peoples R China Chinese Univ Hong Kong, Dept Elect Engn, Shatin, Hong Kong, Peoples R ChinaChow, Chi-Wai论文数: 0 引用数: 0 h-index: 0机构: Natl Chiao Tung Univ, Dept Photon, Hsinchu 30010, Taiwan Chinese Univ Hong Kong, Dept Elect Engn, Shatin, Hong Kong, Peoples R ChinaYeh, Chien-Hung论文数: 0 引用数: 0 h-index: 0机构: Ind Technol Res Inst, Informat & Communicat Res Labs, Hsinchu 31040, Taiwan Fu Jen Catholic Univ, Grad Inst Appl Sci & Engn, New Taipei 24205, Taiwan Chinese Univ Hong Kong, Dept Elect Engn, Shatin, Hong Kong, Peoples R ChinaTsang, Hon Ki论文数: 0 引用数: 0 h-index: 0机构: Chinese Univ Hong Kong, Dept Elect Engn, Shatin, Hong Kong, Peoples R China Chinese Univ Hong Kong, Dept Elect Engn, Shatin, Hong Kong, Peoples R China
- [10] Radiation Damage in Silicon Photonic Mach-Zehnder Modulators and PhotodiodesIEEE TRANSACTIONS ON NUCLEAR SCIENCE, 2017, 64 (11) : 2794 - 2801Zeiler, Marcel论文数: 0 引用数: 0 h-index: 0机构: CERN, Expt Phys Dept, CH-1211 Geneva, Switzerland Dublin City Univ, Sch Elect Engn, Fac Engn & Comp, Dublin 9, Ireland CERN, Expt Phys Dept, CH-1211 Geneva, SwitzerlandEl Nasr-Storey, Sarah Seif论文数: 0 引用数: 0 h-index: 0机构: CERN, Expt Phys Dept, CH-1211 Geneva, Switzerland Univ Bristol, Sch Phys, Fac Sci, Bristol BS8 1TH, Avon, England CERN, Expt Phys Dept, CH-1211 Geneva, SwitzerlandDetraz, Stephane论文数: 0 引用数: 0 h-index: 0机构: CERN, Expt Phys Dept, CH-1211 Geneva, Switzerland CERN, Expt Phys Dept, CH-1211 Geneva, SwitzerlandKraxner, Andrea论文数: 0 引用数: 0 h-index: 0机构: CERN, Expt Phys Dept, CH-1211 Geneva, Switzerland CERN, Expt Phys Dept, CH-1211 Geneva, SwitzerlandOlantera, Lauri论文数: 0 引用数: 0 h-index: 0机构: CERN, Expt Phys Dept, CH-1211 Geneva, Switzerland CERN, Expt Phys Dept, CH-1211 Geneva, SwitzerlandScarcella, Carmelo论文数: 0 引用数: 0 h-index: 0机构: CERN, Expt Phys Dept, CH-1211 Geneva, Switzerland CERN, Expt Phys Dept, CH-1211 Geneva, SwitzerlandSigaud, Christophe论文数: 0 引用数: 0 h-index: 0机构: CERN, Expt Phys Dept, CH-1211 Geneva, Switzerland CERN, Expt Phys Dept, CH-1211 Geneva, SwitzerlandSoos, Csaba论文数: 0 引用数: 0 h-index: 0机构: CERN, Expt Phys Dept, CH-1211 Geneva, Switzerland CERN, Expt Phys Dept, CH-1211 Geneva, SwitzerlandTroska, Jan论文数: 0 引用数: 0 h-index: 0机构: CERN, Expt Phys Dept, CH-1211 Geneva, Switzerland CERN, Expt Phys Dept, CH-1211 Geneva, SwitzerlandVasey, Francois论文数: 0 引用数: 0 h-index: 0机构: CERN, Expt Phys Dept, CH-1211 Geneva, Switzerland CERN, Expt Phys Dept, CH-1211 Geneva, Switzerland