Pub Date : 2002-12-16DOI: 10.1109/ICIMW.2002.1076066
C. Pidgeon, P. Murzyn, J. Wells, N. Gordon, T. Ashley, J. Jefferson, T. Burke, C. Maxey, B. Murdin
The authors have used the Dutch free electron laser (FELIX) to measure spin coherence times in long wavelength Hg/sub 1-x/Cd/sub x/Te at wavelengths between 4 and 10 /spl mu/m and from 4-300K. In particular, they measure remarkably long spin coherence times at 300K.
{"title":"Electron spin coherence in long wavelength Hg/sub 1-x/Cd/sub x/Te","authors":"C. Pidgeon, P. Murzyn, J. Wells, N. Gordon, T. Ashley, J. Jefferson, T. Burke, C. Maxey, B. Murdin","doi":"10.1109/ICIMW.2002.1076066","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076066","url":null,"abstract":"The authors have used the Dutch free electron laser (FELIX) to measure spin coherence times in long wavelength Hg/sub 1-x/Cd/sub x/Te at wavelengths between 4 and 10 /spl mu/m and from 4-300K. In particular, they measure remarkably long spin coherence times at 300K.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77223202","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076061
R. Scheuerer, F. Klappenberger, K. Renk, E. Schomburg, J. Allen, G. R. Ramian, Jeremy S. Scott, Kovsh, V. Ustinov, A. Zhukov
Presents experimental evidence for ultra-fast domain formation in a semiconductor superlattice. An InGaAs/InAlAs superlattice device was mounted in a corner cube. The superlattice device showed a region of negative differential conductance in the current-voltage characteristic for voltages larger than an onset voltage. When the superlattice device was irradiated with radiation smaller than 1.2 THz, the onset voltage shifted, with increasing THz radiation power, to lower voltages. Taking an analysis based on a drift-diffusion model into account, we suggest that dipole domains form within about 400 fs.
{"title":"Ultra-fast domain formation in a semiconductor superlattice","authors":"R. Scheuerer, F. Klappenberger, K. Renk, E. Schomburg, J. Allen, G. R. Ramian, Jeremy S. Scott, Kovsh, V. Ustinov, A. Zhukov","doi":"10.1109/ICIMW.2002.1076061","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076061","url":null,"abstract":"Presents experimental evidence for ultra-fast domain formation in a semiconductor superlattice. An InGaAs/InAlAs superlattice device was mounted in a corner cube. The superlattice device showed a region of negative differential conductance in the current-voltage characteristic for voltages larger than an onset voltage. When the superlattice device was irradiated with radiation smaller than 1.2 THz, the onset voltage shifted, with increasing THz radiation power, to lower voltages. Taking an analysis based on a drift-diffusion model into account, we suggest that dipole domains form within about 400 fs.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77494990","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076157
S. Harriet, D. Mcdermott, N. Luhmann
A second harmonic cusp-gun TE/sub 21/ gyro-TWT amplifier is being constructed at UCD that is predicted to generate 50 kW at 30 GHz with 20% efficiency, 30 dB saturated gain and 3% bandwidth. The device is to be driven by a 70 kV, 3.5 A axis-encircling electron beam from a Northrop Grumman cusp gun. The device takes advantage of the concept that harmonic gyro-TWT's are more stable and can produce higher power than at the fundamental-harmonic, because their weaker interaction yields a higher threshold electron current for the absolute instability at the cutoff of the operating mode.
{"title":"Cusp gun TE/sub 21/ second-harmonic gyro-TWT amplifier","authors":"S. Harriet, D. Mcdermott, N. Luhmann","doi":"10.1109/ICIMW.2002.1076157","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076157","url":null,"abstract":"A second harmonic cusp-gun TE/sub 21/ gyro-TWT amplifier is being constructed at UCD that is predicted to generate 50 kW at 30 GHz with 20% efficiency, 30 dB saturated gain and 3% bandwidth. The device is to be driven by a 70 kV, 3.5 A axis-encircling electron beam from a Northrop Grumman cusp gun. The device takes advantage of the concept that harmonic gyro-TWT's are more stable and can produce higher power than at the fundamental-harmonic, because their weaker interaction yields a higher threshold electron current for the absolute instability at the cutoff of the operating mode.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73842848","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076088
A. I. Fisun, A. V. Arkhipov, O. Belous, B. Bulgakov
The trend for the realization of millimeter wave oscillation systems with a single resonance response in a wide frequency region follows from the many possible applications such as a spectroscopy, radio measurement, and mm wave generation. The using of additional dispersive elements in an open resonator is a dominant way of spectrum rarefaction. The open resonator as an oscillation system for mm wave generator has a number of good points. Investigations of the so-called half-open resonator (HOR) with Gunn diodes and support elements have been carried out. This resonator type appears to have considerable promise for one-diode oscillators and combiners as well as for microwave integrated circuits. This report is devoted to the study the spectral characteristics of a HOR, utilising a diffraction grating, for high Q single mode oscillating systems.
{"title":"Monofrequency excitation of half-open resonator","authors":"A. I. Fisun, A. V. Arkhipov, O. Belous, B. Bulgakov","doi":"10.1109/ICIMW.2002.1076088","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076088","url":null,"abstract":"The trend for the realization of millimeter wave oscillation systems with a single resonance response in a wide frequency region follows from the many possible applications such as a spectroscopy, radio measurement, and mm wave generation. The using of additional dispersive elements in an open resonator is a dominant way of spectrum rarefaction. The open resonator as an oscillation system for mm wave generator has a number of good points. Investigations of the so-called half-open resonator (HOR) with Gunn diodes and support elements have been carried out. This resonator type appears to have considerable promise for one-diode oscillators and combiners as well as for microwave integrated circuits. This report is devoted to the study the spectral characteristics of a HOR, utilising a diffraction grating, for high Q single mode oscillating systems.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87795446","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076224
V. L. Christie, L. Kumar, N. Balakrishnan
A design procedure for an inter-digital slow-wave structure for TWTs is presented using equivalent circuit approach. The results are refined using numerical simulations by modeling the structure using the software package MAFIA. The dimensions of the inter-digital structure are compared with those of a conventional coupled-cavity slow-wave structure designed at the same center frequency. It is concluded that the size and weight of the inter-digital structure is significantly reduced as compared to that of a coupled-cavity structure.
{"title":"The design of an inter-digital structure for TWTs","authors":"V. L. Christie, L. Kumar, N. Balakrishnan","doi":"10.1109/ICIMW.2002.1076224","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076224","url":null,"abstract":"A design procedure for an inter-digital slow-wave structure for TWTs is presented using equivalent circuit approach. The results are refined using numerical simulations by modeling the structure using the software package MAFIA. The dimensions of the inter-digital structure are compared with those of a conventional coupled-cavity slow-wave structure designed at the same center frequency. It is concluded that the size and weight of the inter-digital structure is significantly reduced as compared to that of a coupled-cavity structure.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89656697","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076191
Q. Xiao, K. Wade Nye, J.L. Hester, T. Crowe
This paper discusses the techniques used to design a 300 GHz to 400 GHz integrated beam-lead varistor quadrupler. Nonlinear simulations were performed to calculate the optimum diode embedding impedance and the required input power. A finite-element analysis program (HFSS) was used to design the matching network.
{"title":"The design and analysis of a 350 GHz wide band beam-lead varistor quadrupler","authors":"Q. Xiao, K. Wade Nye, J.L. Hester, T. Crowe","doi":"10.1109/ICIMW.2002.1076191","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076191","url":null,"abstract":"This paper discusses the techniques used to design a 300 GHz to 400 GHz integrated beam-lead varistor quadrupler. Nonlinear simulations were performed to calculate the optimum diode embedding impedance and the required input power. A finite-element analysis program (HFSS) was used to design the matching network.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91459482","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076047
E. Brown, D. Woolard, A. Samuels, T. Globus, B. Gelmont
A first-pass analysis is carried out of a 421 GHz coherent radar to detect the presence of a bioparticle cloud at a stand-off of 1 km. Compared to the incoherent radar performance under identical field conditions, the coherent system achieves a post-demodulator signal-to-noise ratio roughly 300 times higher and far superior probabilities of detection and false alarm.
{"title":"Toward the detection of bioparticles by radar in the THz region","authors":"E. Brown, D. Woolard, A. Samuels, T. Globus, B. Gelmont","doi":"10.1109/ICIMW.2002.1076047","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076047","url":null,"abstract":"A first-pass analysis is carried out of a 421 GHz coherent radar to detect the presence of a bioparticle cloud at a stand-off of 1 km. Compared to the incoherent radar performance under identical field conditions, the coherent system achieves a post-demodulator signal-to-noise ratio roughly 300 times higher and far superior probabilities of detection and false alarm.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81333251","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076086
K.W. Nye, Q. Xiao, J. Hesler, T. Crowe
Backside wafer processing has been developed for discrete beamlead diodes and beamlead MMICs. Backside etching allows arbitrary substrate geometry. The beamleads are used to make electrical connections to a waveguide block and/or serve as substrateless transmission lines. The fabrication of an 82.5 to 330 GHz MMIC balanced frequency quadrupler is presented.
{"title":"Novel fabrication of integrated submillimeter circuits","authors":"K.W. Nye, Q. Xiao, J. Hesler, T. Crowe","doi":"10.1109/ICIMW.2002.1076086","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076086","url":null,"abstract":"Backside wafer processing has been developed for discrete beamlead diodes and beamlead MMICs. Backside etching allows arbitrary substrate geometry. The beamleads are used to make electrical connections to a waveguide block and/or serve as substrateless transmission lines. The fabrication of an 82.5 to 330 GHz MMIC balanced frequency quadrupler is presented.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80018419","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076215
H. Ohta, K. Kawakami, S. Okubo, Y. Inagaki, T. Kunimoto, Z. Hiroi
BaCu/sub 2/(Si/sub 1-x/Ge/sub x/)/sub 2/O/sub 7/ (x=0.65) is a one dimensional antiferromagnet (1D AF) with the staggered g-tensor and Dzyaloshinskii-Moriya (DM) interaction. Although the system is expected to have intrinsic randomness, our submillimeter wave ESR results show the typical behavior of the 1D AF and they are discussed along with the recent ESR theory of Oshikawa and Affleck (Phys. Rev. Lett. vol. 82, p. 5136, 1999).
{"title":"One dimensional behavior of mixed crystal BaCu/sub 2/(Si/sub 1-x/Ge/sub x/)/sub 2/O/sub 7/ observed by submillimeter wave ESR","authors":"H. Ohta, K. Kawakami, S. Okubo, Y. Inagaki, T. Kunimoto, Z. Hiroi","doi":"10.1109/ICIMW.2002.1076215","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076215","url":null,"abstract":"BaCu/sub 2/(Si/sub 1-x/Ge/sub x/)/sub 2/O/sub 7/ (x=0.65) is a one dimensional antiferromagnet (1D AF) with the staggered g-tensor and Dzyaloshinskii-Moriya (DM) interaction. Although the system is expected to have intrinsic randomness, our submillimeter wave ESR results show the typical behavior of the 1D AF and they are discussed along with the recent ESR theory of Oshikawa and Affleck (Phys. Rev. Lett. vol. 82, p. 5136, 1999).","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78440344","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076189
J. Hovenier, T. Klaassen, R. Zhukavin, D. M. Gaponova, A. Muravjov, E. Orlova, V. Shastin, S. Pavlov, H. Hubers, H. Riemann, A. V. D. van der Meer
Frequency tunable radiation from the free electron laser FELIX was used to excite neutral phosphorus and bismuth donors embedded in bulk monocrystalline silicon. Lasing at terahertz frequencies has been observed at liquid helium temperature under resonant pumping of odd parity impurity states.
{"title":"Stimulated THz emission from Si:P and Si:Bi under resonant intracenter optical pumping","authors":"J. Hovenier, T. Klaassen, R. Zhukavin, D. M. Gaponova, A. Muravjov, E. Orlova, V. Shastin, S. Pavlov, H. Hubers, H. Riemann, A. V. D. van der Meer","doi":"10.1109/ICIMW.2002.1076189","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076189","url":null,"abstract":"Frequency tunable radiation from the free electron laser FELIX was used to excite neutral phosphorus and bismuth donors embedded in bulk monocrystalline silicon. Lasing at terahertz frequencies has been observed at liquid helium temperature under resonant pumping of odd parity impurity states.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82808415","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}
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