Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference on 2004 and 12th International Conference on Terahertz Electronics, 2004.最新文献
Pub Date : 2004-12-01DOI: 10.1109/ICIMW.2004.1422227
I. Gregory, T. Drysdale, W. Tribe, D. Cumming, M. Evans, M. Missous, E. Linfield
We have constructed a continuous-wave terahertz imaging system based on diode lasers, a photoconductive emitter, and a phase-sensitive photoconductive receiver. It is inexpensive and compact, but with a performance comparable with established pulsed terahertz systems. We also use a novel photonic crystal filter to remove unwanted low frequency noise components.
{"title":"A high performance CW-THz photomixing imaging system","authors":"I. Gregory, T. Drysdale, W. Tribe, D. Cumming, M. Evans, M. Missous, E. Linfield","doi":"10.1109/ICIMW.2004.1422227","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422227","url":null,"abstract":"We have constructed a continuous-wave terahertz imaging system based on diode lasers, a photoconductive emitter, and a phase-sensitive photoconductive receiver. It is inexpensive and compact, but with a performance comparable with established pulsed terahertz systems. We also use a novel photonic crystal filter to remove unwanted low frequency noise components.","PeriodicalId":13627,"journal":{"name":"Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference on 2004 and 12th International Conference on Terahertz Electronics, 2004.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72838312","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}
Pub Date : 2004-12-01DOI: 10.1109/ICIMW.2004.1422237
R. Fiorito, J. Neumann, H. Freund, P. O'Shea, H. Loos, B. Sheehy, G. Carr, W. Graves
A bunched electron beam is an efficient source of coherent radiation at wavelengths longer than the bunch length. We describe an experiment demonstrating electron density modulation at 0.8 THz using an optically modulated drive laser to extract a prebunched beam from an RF photoinjector, which is preserved through acceleration to 75 MeV. Measurements of coherent THz transition radiation (CTTR) are presented at the prebunch frequency showing enhanced production over that produced from an unmodulated beam.
{"title":"Coherent terahertz radiation from optically pre-bunched electron beams","authors":"R. Fiorito, J. Neumann, H. Freund, P. O'Shea, H. Loos, B. Sheehy, G. Carr, W. Graves","doi":"10.1109/ICIMW.2004.1422237","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422237","url":null,"abstract":"A bunched electron beam is an efficient source of coherent radiation at wavelengths longer than the bunch length. We describe an experiment demonstrating electron density modulation at 0.8 THz using an optically modulated drive laser to extract a prebunched beam from an RF photoinjector, which is preserved through acceleration to 75 MeV. Measurements of coherent THz transition radiation (CTTR) are presented at the prebunch frequency showing enhanced production over that produced from an unmodulated beam.","PeriodicalId":13627,"journal":{"name":"Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference on 2004 and 12th International Conference on Terahertz Electronics, 2004.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79366552","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}
Pub Date : 2004-12-01DOI: 10.1109/ICIMW.2004.1422114
C. Baker, I. Gregory, W. Tribe, M. Evans, M. Missous, E. Linfield
Highly-resistive low-temperature grown InGaAs, with a sub-500 fs carrier lifetime, is used as an all-optoelectronic continuous-wave terahertz photomixer system based on diode lasers. Interdigitated electrodes fabricated on epitaxial low-temperature grown In/sub 0.3/Ga/sub 0.7/As are used as photomixers to generate and detect radiation from microwave frequencies (<100 GHz) to beyond 1.0 THz.
{"title":"Continuous-wave terahertz photomixing in low-temperature InGaAs","authors":"C. Baker, I. Gregory, W. Tribe, M. Evans, M. Missous, E. Linfield","doi":"10.1109/ICIMW.2004.1422114","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422114","url":null,"abstract":"Highly-resistive low-temperature grown InGaAs, with a sub-500 fs carrier lifetime, is used as an all-optoelectronic continuous-wave terahertz photomixer system based on diode lasers. Interdigitated electrodes fabricated on epitaxial low-temperature grown In/sub 0.3/Ga/sub 0.7/As are used as photomixers to generate and detect radiation from microwave frequencies (<100 GHz) to beyond 1.0 THz.","PeriodicalId":13627,"journal":{"name":"Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference on 2004 and 12th International Conference on Terahertz Electronics, 2004.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78599531","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}
Pub Date : 2004-12-01DOI: 10.1109/ICIMW.2004.1422203
V. Tamošiūnas, R. Zobl, G. Fasching, G. Strasser, K. Unterrianer, R. Colombelli, C. Gmachl, L.N. Pfiffer, K. West, F. Capasso
We report on the influence of a quantizing magnetic field on a THz quantum cascade laser. The magnetic field splits the subbands into sets of discrete Landau levels, which reduces the phase space for scattering and relaxation. A dramatic enhancement of the laser performance is achieved.
{"title":"Magnetic modulation of THz quantum cascade lasers","authors":"V. Tamošiūnas, R. Zobl, G. Fasching, G. Strasser, K. Unterrianer, R. Colombelli, C. Gmachl, L.N. Pfiffer, K. West, F. Capasso","doi":"10.1109/ICIMW.2004.1422203","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422203","url":null,"abstract":"We report on the influence of a quantizing magnetic field on a THz quantum cascade laser. The magnetic field splits the subbands into sets of discrete Landau levels, which reduces the phase space for scattering and relaxation. A dramatic enhancement of the laser performance is achieved.","PeriodicalId":13627,"journal":{"name":"Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference on 2004 and 12th International Conference on Terahertz Electronics, 2004.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77062677","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}
Pub Date : 2004-11-01DOI: 10.1109/ICIMW.2004.1422271
L. Ives, T. Bui, W. Vogler, J. Neilson, V. Peoples, A. Bauer, M. Shephard, H. Tran, M. Beall
A new, finite element, adaptive mesh trajectory code is available for designing electron devices, including electron guns and collectors. The finite element technique provides for more efficient simulation of particles in electromagnetic fields, and the adaptive meshing insures optimal use of computational resources. The adaptive meshing removes responsibility from the user for mesh generation and allows for dramatic simplification of code operation. The code imports geometry from commercial CAD programs and includes an intuitive, user-friendly, graphical user interface and post processor.
{"title":"3D finite element trajectory code with adaptive meshing","authors":"L. Ives, T. Bui, W. Vogler, J. Neilson, V. Peoples, A. Bauer, M. Shephard, H. Tran, M. Beall","doi":"10.1109/ICIMW.2004.1422271","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422271","url":null,"abstract":"A new, finite element, adaptive mesh trajectory code is available for designing electron devices, including electron guns and collectors. The finite element technique provides for more efficient simulation of particles in electromagnetic fields, and the adaptive meshing insures optimal use of computational resources. The adaptive meshing removes responsibility from the user for mesh generation and allows for dramatic simplification of code operation. The code imports geometry from commercial CAD programs and includes an intuitive, user-friendly, graphical user interface and post processor.","PeriodicalId":13627,"journal":{"name":"Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference on 2004 and 12th International Conference on Terahertz Electronics, 2004.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2004-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85712361","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}
A theory describing the influence of reflections on operation of gyrotrons with radial output is presented. The theory is used for evaluating the effect of reflections on the operation of the 170 GHz ITER coaxial cavity gyrotron. It is shown that for optimally chosen external magnetic field value and electron beam radius, possible reflections do not change the final steady-state operation, which corresponds to generation of a 2.2 MW power.
{"title":"Reflections in gyrotrons with radial output: consequences for the ITER coaxial gyrotron","authors":"O. Dumbrajs, G. Nusinovich, B. Piosczyk","doi":"10.1063/1.1810161","DOIUrl":"https://doi.org/10.1063/1.1810161","url":null,"abstract":"A theory describing the influence of reflections on operation of gyrotrons with radial output is presented. The theory is used for evaluating the effect of reflections on the operation of the 170 GHz ITER coaxial cavity gyrotron. It is shown that for optimally chosen external magnetic field value and electron beam radius, possible reflections do not change the final steady-state operation, which corresponds to generation of a 2.2 MW power.","PeriodicalId":13627,"journal":{"name":"Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference on 2004 and 12th International Conference on Terahertz Electronics, 2004.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2004-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87186122","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}
Pub Date : 2004-09-30DOI: 10.1109/ICIMW.2004.1422225
C. Tripon-Canseliet, A. Maestrini, I. Mehdi
We report on the design of a fix-tuned split-block waveguide balanced frequency tripler working nominally at 900 GHz. It uses a GaAs Schottky planar diode pair in a balanced configuration. The circuit is fabricated with JPL membrane technology in order to minimize dielectric loading. The multiplier is bias-less to dramatically ease the mounting and the operating procedure. At room temperature, the expected output power is 50-130 /spl mu/W in the band 800-970 GHz when the tripler is pumped with 4 mW. By modifying the waveguide input and output matching circuit, the multiplier can be tuned to operate at lower frequencies.
{"title":"Design of a wideband 900 GHz balanced frequency tripler for radioastronomy","authors":"C. Tripon-Canseliet, A. Maestrini, I. Mehdi","doi":"10.1109/ICIMW.2004.1422225","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422225","url":null,"abstract":"We report on the design of a fix-tuned split-block waveguide balanced frequency tripler working nominally at 900 GHz. It uses a GaAs Schottky planar diode pair in a balanced configuration. The circuit is fabricated with JPL membrane technology in order to minimize dielectric loading. The multiplier is bias-less to dramatically ease the mounting and the operating procedure. At room temperature, the expected output power is 50-130 /spl mu/W in the band 800-970 GHz when the tripler is pumped with 4 mW. By modifying the waveguide input and output matching circuit, the multiplier can be tuned to operate at lower frequencies.","PeriodicalId":13627,"journal":{"name":"Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference on 2004 and 12th International Conference on Terahertz Electronics, 2004.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2004-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81961424","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}
Pub Date : 2004-09-29DOI: 10.1109/ICIMW.2004.1422319
F. Maiwald, J. Pearson, J. Ward, E. Schlecht, G. Chattopadhyay, J. Gill, R. Ferber, R. Tsang, R. Lin, A. Peralta, B. Finamore, W. Chun, J. Baker, R. Dengler, H. Javadi, P. Siegel, I. Mehdi
This paper discusses the construction of solid-state frequency multiplier chains utilized for terahertz receiver applications such as the Herschel Space Observatory. Emphasis is placed on the specific requirements to be met and challenges that were encountered. The availability of high power amplifiers at 100 GHz makes it possible to cascade frequency doublers and triplers with sufficient RF power to pump heterodyne receivers at THz frequencies. The environmental and mechanical constraints are addressed as well as reliability issues.
{"title":"Solid-state terahertz sources for space applications","authors":"F. Maiwald, J. Pearson, J. Ward, E. Schlecht, G. Chattopadhyay, J. Gill, R. Ferber, R. Tsang, R. Lin, A. Peralta, B. Finamore, W. Chun, J. Baker, R. Dengler, H. Javadi, P. Siegel, I. Mehdi","doi":"10.1109/ICIMW.2004.1422319","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422319","url":null,"abstract":"This paper discusses the construction of solid-state frequency multiplier chains utilized for terahertz receiver applications such as the Herschel Space Observatory. Emphasis is placed on the specific requirements to be met and challenges that were encountered. The availability of high power amplifiers at 100 GHz makes it possible to cascade frequency doublers and triplers with sufficient RF power to pump heterodyne receivers at THz frequencies. The environmental and mechanical constraints are addressed as well as reliability issues.","PeriodicalId":13627,"journal":{"name":"Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference on 2004 and 12th International Conference on Terahertz Electronics, 2004.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2004-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89324222","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}
Pub Date : 2004-09-28DOI: 10.1109/ICIMW.2004.1422025
A. Maestrini, C. Tripon-Canseliet, I. Mehdi
We report on the design methodology of a fix-tuned split-block waveguide balanced frequency tripler working nominally at 300 GHz. It features six GaAs Schottky planar diodes in a balanced configuration. The circuit is fabricated with JPL membrane technology in order to minimize dielectric loading and insure an accurate and uniform thickness of the substrate. The multiplier power handling is limited by the breakdown voltage of the diodes that depends on the doping level of the active layer. With six diodes, the current choice for the doping level leads to medium power handling capabilities of about 50 mW. Increasing the number of diodes to eight is an option but lead to increased difficulties in design and fabrication.
{"title":"Design of a wideband 6-anode frequency tripler at 300 GHz with optimum balance","authors":"A. Maestrini, C. Tripon-Canseliet, I. Mehdi","doi":"10.1109/ICIMW.2004.1422025","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422025","url":null,"abstract":"We report on the design methodology of a fix-tuned split-block waveguide balanced frequency tripler working nominally at 300 GHz. It features six GaAs Schottky planar diodes in a balanced configuration. The circuit is fabricated with JPL membrane technology in order to minimize dielectric loading and insure an accurate and uniform thickness of the substrate. The multiplier power handling is limited by the breakdown voltage of the diodes that depends on the doping level of the active layer. With six diodes, the current choice for the doping level leads to medium power handling capabilities of about 50 mW. Increasing the number of diodes to eight is an option but lead to increased difficulties in design and fabrication.","PeriodicalId":13627,"journal":{"name":"Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference on 2004 and 12th International Conference on Terahertz Electronics, 2004.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2004-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90114141","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}
Pub Date : 2004-09-27DOI: 10.1109/ICIMW.2004.1422210
P. Siegel, R. Dengler
The authors present a description and early measurement results from a unique CW terahertz heterodyne imaging system based around two custom fabricated 2.5 THz planar Schottky diode mixers and two commercially available optically pumped far IR lasers. One laser is used for the signal beam and supplies as much as 70 mW at 2.5 THz. The other laser acts as a local oscillator source for the two mixers. The system uses the second THz mixer, a low frequency reference oscillator and a lock-in amplifier to monitor and normalise the two lasers. The system has been employed on both biological tissues as well as materials of interest to NASA space science applications. The instrumentation is briefly described and some representative images is also presented.
{"title":"Applications & early results from THz heterodyne imaging at 119 /spl mu/m","authors":"P. Siegel, R. Dengler","doi":"10.1109/ICIMW.2004.1422210","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422210","url":null,"abstract":"The authors present a description and early measurement results from a unique CW terahertz heterodyne imaging system based around two custom fabricated 2.5 THz planar Schottky diode mixers and two commercially available optically pumped far IR lasers. One laser is used for the signal beam and supplies as much as 70 mW at 2.5 THz. The other laser acts as a local oscillator source for the two mixers. The system uses the second THz mixer, a low frequency reference oscillator and a lock-in amplifier to monitor and normalise the two lasers. The system has been employed on both biological tissues as well as materials of interest to NASA space science applications. The instrumentation is briefly described and some representative images is also presented.","PeriodicalId":13627,"journal":{"name":"Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference on 2004 and 12th International Conference on Terahertz Electronics, 2004.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90563530","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}
Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference on 2004 and 12th International Conference on Terahertz Electronics, 2004.
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