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1981 International Conference on Submillimeter Waves and Their Applications最新文献

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Theory on Distributed Feedback (DFB) Lasers with Strong Periodic Modulations 强周期调制分布反馈(DFB)激光器理论
1981 International Conference on Submillimeter Waves and Their Applications Pub Date : 1981-12-01 DOI: 10.1109/ICSWA.1981.9335213
S. Gnepf, H. Preiswerk, F. Kneubühl
{"title":"Theory on Distributed Feedback (DFB) Lasers with Strong Periodic Modulations","authors":"S. Gnepf, H. Preiswerk, F. Kneubühl","doi":"10.1109/ICSWA.1981.9335213","DOIUrl":"https://doi.org/10.1109/ICSWA.1981.9335213","url":null,"abstract":"DFB (Distributed Feedback) lasers do not use conventional resonator mirrors, but provide feedback via backward Bragg scattering from periodic modulations of refractive index and/or gain of the iaser medium. An important feature is the high spectral selectivity which originates in the Bragg effect and allows selection of longitudinal modes |l|. Hitherto, DFB theories were restricted to small modulations |2,3,4,5|. In this paper, we study the effects of strong DFB modulations on the basis of a complex Hill equation which can be solved analytically. This procedure provides for the first time a direct access to the complex characteristics of future DFB lasers with strong modulations.","PeriodicalId":254777,"journal":{"name":"1981 International Conference on Submillimeter Waves and Their Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129772230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
D2O Laser Thomson Scattering and Submillimeter Heterodyne Receiver Measurements D2O激光汤姆逊散射和亚毫米外差接收机测量
1981 International Conference on Submillimeter Waves and Their Applications Pub Date : 1981-12-01 DOI: 10.1109/ICSWA.1981.9335093
P. Woskoboinikow, H. Praddaude, W. Mulligan, D. Cohn, B. Lax, H. Fetterman
{"title":"D2O Laser Thomson Scattering and Submillimeter Heterodyne Receiver Measurements","authors":"P. Woskoboinikow, H. Praddaude, W. Mulligan, D. Cohn, B. Lax, H. Fetterman","doi":"10.1109/ICSWA.1981.9335093","DOIUrl":"https://doi.org/10.1109/ICSWA.1981.9335093","url":null,"abstract":"The MIT program to develop high power collective Thomson scattering diagnostics will be presented. All elements of a 385 μm D2O laser Thomson scattering diagnostic are in place and operational on the Alcator C tokamak. Major components include: a 0.5 MW, 150 ns D2O laser; a heterodyne receiver using a corner reflector mounted Schottky diode mixer and a 25 mW, 381 μm DCOOD laser local oscillator; and x-band I.F. electronics including a 32 channel multiplexer filter centered at 9.4 GHz with 80 MHz wide channels. Receiver noise temperatures (not including signal collection optics) of 15,000-20,000 K double sideband (DSB) have been measured for individual filter channels. Additional details of the D2O laser, the receiver and the overall implementation of this diagnostic on Alcator C have been described previously [1-3].","PeriodicalId":254777,"journal":{"name":"1981 International Conference on Submillimeter Waves and Their Applications","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132916755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Microwave Wide Aperture Standard Noise Sources for Antenna Parameters Measurements in Millimeter Frequency Band 毫米波波段天线参数测量的微波大孔径标准噪声源
1981 International Conference on Submillimeter Waves and Their Applications Pub Date : 1981-12-01 DOI: 10.1109/ICSWA.1981.9335216
V. Lander
{"title":"Microwave Wide Aperture Standard Noise Sources for Antenna Parameters Measurements in Millimeter Frequency Band","authors":"V. Lander","doi":"10.1109/ICSWA.1981.9335216","DOIUrl":"https://doi.org/10.1109/ICSWA.1981.9335216","url":null,"abstract":"Very accurate antenna parameters measurement technique which implements wide aperture noise sources is described. Construction of the wide aperture microwave noise radiators is discussed. The system can reproduce the noise temperature from 103K to 105K with accuracy 2%-8%.","PeriodicalId":254777,"journal":{"name":"1981 International Conference on Submillimeter Waves and Their Applications","volume":"100 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133721009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Recent Advances in High Power Millimeter Wave Traveling Wave Tubes 大功率毫米波行波管的研究进展
1981 International Conference on Submillimeter Waves and Their Applications Pub Date : 1981-12-01 DOI: 10.1109/ICSWA.1981.9335109
J. J. Hamilton, R. Harper, U. Pittack
{"title":"Recent Advances in High Power Millimeter Wave Traveling Wave Tubes","authors":"J. J. Hamilton, R. Harper, U. Pittack","doi":"10.1109/ICSWA.1981.9335109","DOIUrl":"https://doi.org/10.1109/ICSWA.1981.9335109","url":null,"abstract":"Recent work performed at Raytheon on three different types of high power millimeter wave traveling-wave tubes is outlined. The first design addresses the problem of high CW power, while the second focuses on broadband performance. The third is aimed at the non-trival subject of millimeter wave amplifier cost.","PeriodicalId":254777,"journal":{"name":"1981 International Conference on Submillimeter Waves and Their Applications","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133584000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Frequency Tuning and Efficiency Enhancement of High Power FIR Lasers 高功率FIR激光器的频率调谐与效率提高
1981 International Conference on Submillimeter Waves and Their Applications Pub Date : 1981-12-01 DOI: 10.1109/ICSWA.1981.9335210
B. Danly, R. Temkin, B. Lax
{"title":"Frequency Tuning and Efficiency Enhancement of High Power FIR Lasers","authors":"B. Danly, R. Temkin, B. Lax","doi":"10.1109/ICSWA.1981.9335210","DOIUrl":"https://doi.org/10.1109/ICSWA.1981.9335210","url":null,"abstract":"National Magnet Laboratory Massachusetts Institute of Technology Cambridge, Mass. 02139 Introduction Laser pumped molecular lasers have many useful applications including radar, plasma diagnostics and spectroscopy. This range of applications would be expanded considerably with the development of highly efficient and/or frequency tunable laser pumped lasers. In this paper, we describe techniques for achieving these goals, techniques based on excitation of a molecular gas far off resonance. We have already demonstrated such excitation in CO2 laser pumping of CH3F gas. Experimental and theoretical work has been carried out on a tunable far infrared (FIR) laser based on Raman scattering of tunable CO2 laser pump radiation in molecular gases. Good agreement between theory and experiment is obtained. Stimulated multiphoton emission processes are considered as a method of achieving efficiency enhancement in laser pumped lasers. These processes achieve high efficiency through the simultaneous emission of several low frequency photons for each high frequency photon absorbed.","PeriodicalId":254777,"journal":{"name":"1981 International Conference on Submillimeter Waves and Their Applications","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133167047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
A MM-Wave Collision Warning Device for Helicopters 直升机毫米波碰撞预警装置
1981 International Conference on Submillimeter Waves and Their Applications Pub Date : 1981-12-01 DOI: 10.1109/ICSWA.1981.9335204
B. Rembold, H. Wippich, Miriam B. Bischoff, Werner F. X. Frank
{"title":"A MM-Wave Collision Warning Device for Helicopters","authors":"B. Rembold, H. Wippich, Miriam B. Bischoff, Werner F. X. Frank","doi":"10.1109/ICSWA.1981.9335204","DOIUrl":"https://doi.org/10.1109/ICSWA.1981.9335204","url":null,"abstract":"A mm-wave radar has been developed having sufficient range to give reliable and timely warning of upcoming obstacles, expecially high voltage transmission lines. A description of the radar as well as first measured results will be presented.","PeriodicalId":254777,"journal":{"name":"1981 International Conference on Submillimeter Waves and Their Applications","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132694699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 16
Reflectivity of Some Materials; at 94 GHz 某些材料的反射率;在94 GHz
1981 International Conference on Submillimeter Waves and Their Applications Pub Date : 1981-12-01 DOI: 10.1109/ICSWA.1981.9335135
P. Alexander
{"title":"Reflectivity of Some Materials; at 94 GHz","authors":"P. Alexander","doi":"10.1109/ICSWA.1981.9335135","DOIUrl":"https://doi.org/10.1109/ICSWA.1981.9335135","url":null,"abstract":"In order to better understand the characteristics of discrete natural land clutter at millimeter wavelengths, an experimental investigation of the relative reflectivity of various materials at 94 GHz was performed using a substitution technique. The data show that nonconducting materials have a relative reflectivity on the order of 2-3%, and that absorbed water can increase the relative reflectivity significantly.","PeriodicalId":254777,"journal":{"name":"1981 International Conference on Submillimeter Waves and Their Applications","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116797937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Wave Guiding of Far Infrared Radiation for the Jet Interferometer 射流干涉仪对远红外辐射的导波
1981 International Conference on Submillimeter Waves and Their Applications Pub Date : 1981-12-01 DOI: 10.1109/ICSWA.1981.9335165
J. P. Crenn, D. Véron
{"title":"Wave Guiding of Far Infrared Radiation for the Jet Interferometer","authors":"J. P. Crenn, D. Véron","doi":"10.1109/ICSWA.1981.9335165","DOIUrl":"https://doi.org/10.1109/ICSWA.1981.9335165","url":null,"abstract":"The far infrared interferometer being designed to measure the electron density of the JET plasma will use waveguiding for beam propagation. An experimental 30 m long waveguide set-up is studied, using the 0,195 mm wavelength radiation of a DCN laser. The main characteristics of the guided beam are measured as a function of the angle of incidence. Transmissions up to 60 % are observed and the degree of polarization is kept to a high level in the case of a 60 mm diameter glass waveguide.","PeriodicalId":254777,"journal":{"name":"1981 International Conference on Submillimeter Waves and Their Applications","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122355566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Photoexcited Cyclotron Resonance in Semiconductors at Far-Infrared 半导体远红外光激回旋共振
1981 International Conference on Submillimeter Waves and Their Applications Pub Date : 1981-12-01 DOI: 10.1109/ICSWA.1981.9335080
T. Ohyama
{"title":"Photoexcited Cyclotron Resonance in Semiconductors at Far-Infrared","authors":"T. Ohyama","doi":"10.1109/ICSWA.1981.9335080","DOIUrl":"https://doi.org/10.1109/ICSWA.1981.9335080","url":null,"abstract":"The far-infrared (84-220 μm) laser cyclotron resonance, impurity-Zeeman absorption and exciton-Zeeman absorption under the intrinsic photoexcitation are described for Ge, Si, InSb and GaAs. Through time-resolved experiments, the optically hot electron state and carrier relaxation as well as recombination mechanism are investigated.","PeriodicalId":254777,"journal":{"name":"1981 International Conference on Submillimeter Waves and Their Applications","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122370522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Recent Theoretical Developments in Gyrotron Research 回旋管研究的最新理论进展
1981 International Conference on Submillimeter Waves and Their Applications Pub Date : 1981-12-01 DOI: 10.1109/ICSWA.1981.9335148
K. Chu
{"title":"Recent Theoretical Developments in Gyrotron Research","authors":"K. Chu","doi":"10.1109/ICSWA.1981.9335148","DOIUrl":"https://doi.org/10.1109/ICSWA.1981.9335148","url":null,"abstract":"An electromagnetic radiation mechanism1-3 known as the “electron cyclotron maser” has been the basis of a new class of radiation devices, called the gyrotrons, capable of generating coherent millimeter and submillimeter radiation at unprecedented power levels. The cyclotron maser interaction takes place between the electromagnetic waves of a cavity or waveguide structure and an electron beam in which the individual electrons move along helical trajectories in the presence of an applied magnetic field. Theory and development of various types of gyrotrons can be found in recent review articles4-8 and the references cited therein.","PeriodicalId":254777,"journal":{"name":"1981 International Conference on Submillimeter Waves and Their Applications","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125451717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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