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 : 2004-01-01DOI: 10.1109/ICIMW.2004.1422180
J. Cao
Nonlinear free-carrier absorption of terahertz radiations in semiconductor heterojunctions have theoretically been investigated by considering multiple photon process and conduction-valence interband impact ionisation (II). We have determined the field and frequency dependent absorption rate. It is found that electron-disorder scatterings are important at low to intermediate fields, and the high field absorption is dominated by II processes.
{"title":"Absorption of terahertz radiations in two-dimensional semiconductors","authors":"J. Cao","doi":"10.1109/ICIMW.2004.1422180","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422180","url":null,"abstract":"Nonlinear free-carrier absorption of terahertz radiations in semiconductor heterojunctions have theoretically been investigated by considering multiple photon process and conduction-valence interband impact ionisation (II). We have determined the field and frequency dependent absorption rate. It is found that electron-disorder scatterings are important at low to intermediate fields, and the high field absorption is dominated by II processes.","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":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78078369","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 : 2004-01-01DOI: 10.1109/ICIMW.2004.1422143
A. Priebe, G. Fahsold, A. Pucci
The surface enhanced infrared absorption (SEIRA) of adsorbates on nano-structured metal films is widely exploited in chemistry and biology, but the basic effects are only partially understood. Our IR transmittance studies of thin metal films under ultra-high vacuum (UHV) conditions showed two types of SEIRA lines. The systems investigated were C/sub 2/H/sub 4/ and C/sub 2/H/sub 6/, respectively, on cold-deposited Cu films, on transparent substrates (MgO, KBr) and on Cu films prepared at room temperature on the same substrates. For the room-temperature films only the IR-active vibrations of the adsorbates give SEIRA lines, which can be explained by interaction of the molecules with the electromagnetic field. On cold-deposited films also Raman-active lines of C/sub 2/H/sub 4/ appear in the IR-transmittance spectra. These lines saturate already below monolayer coverage. For C/sub 2/H/sub 6/ Raman bands like in SERS of C/sub 2/H/sub 6/ on cold-deposited silver are not observed. The appearance of the Raman lines of centrosymmetric molecules in the IR spectra is a first-layer effect and should be due to an indirect excitation mechanism involving metal electrons. For this mechanism roughness on an atomic scale and an adsorbate /spl pi/* state are important.
{"title":"The enhanced infrared absorption on different types of metal nano-particle films","authors":"A. Priebe, G. Fahsold, A. Pucci","doi":"10.1109/ICIMW.2004.1422143","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422143","url":null,"abstract":"The surface enhanced infrared absorption (SEIRA) of adsorbates on nano-structured metal films is widely exploited in chemistry and biology, but the basic effects are only partially understood. Our IR transmittance studies of thin metal films under ultra-high vacuum (UHV) conditions showed two types of SEIRA lines. The systems investigated were C/sub 2/H/sub 4/ and C/sub 2/H/sub 6/, respectively, on cold-deposited Cu films, on transparent substrates (MgO, KBr) and on Cu films prepared at room temperature on the same substrates. For the room-temperature films only the IR-active vibrations of the adsorbates give SEIRA lines, which can be explained by interaction of the molecules with the electromagnetic field. On cold-deposited films also Raman-active lines of C/sub 2/H/sub 4/ appear in the IR-transmittance spectra. These lines saturate already below monolayer coverage. For C/sub 2/H/sub 6/ Raman bands like in SERS of C/sub 2/H/sub 6/ on cold-deposited silver are not observed. The appearance of the Raman lines of centrosymmetric molecules in the IR spectra is a first-layer effect and should be due to an indirect excitation mechanism involving metal electrons. For this mechanism roughness on an atomic scale and an adsorbate /spl pi/* state are important.","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":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79970534","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 : 2004-01-01DOI: 10.1109/ICIMW.2004.1422093
T. Otsuji, M. Hanabe, J. Shigenobu, S. Takahashi, E. Sano
Two-dimensional (2D) plasmon in a submicron transistor channel can make resonant oscillation in the terahertz range. We propose a novel terahertz plasma-wave photomixer that can improve the conversion gain and terahertz radiation power. The photomixer is based on a high-electron mobility transistor (HEMT) and incorporates doubly interdigitated grating strips for the gate electrodes that periodically localize the 2D plasmons in sub 100-nm regions with a micron-order interval. A vertical cavity structure is formed in between the top metal grating and a terahertz mirror placed at the backside. FDTD simulation demonstrates that a newly-introduced vertical cavity structure effectively enhances the conversion gain and radiation power.
{"title":"A novel terahertz plasma-wave photomixer with resonant-cavity enhanced structure","authors":"T. Otsuji, M. Hanabe, J. Shigenobu, S. Takahashi, E. Sano","doi":"10.1109/ICIMW.2004.1422093","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422093","url":null,"abstract":"Two-dimensional (2D) plasmon in a submicron transistor channel can make resonant oscillation in the terahertz range. We propose a novel terahertz plasma-wave photomixer that can improve the conversion gain and terahertz radiation power. The photomixer is based on a high-electron mobility transistor (HEMT) and incorporates doubly interdigitated grating strips for the gate electrodes that periodically localize the 2D plasmons in sub 100-nm regions with a micron-order interval. A vertical cavity structure is formed in between the top metal grating and a terahertz mirror placed at the backside. FDTD simulation demonstrates that a newly-introduced vertical cavity structure effectively enhances the conversion gain and radiation 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":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76763729","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 : 2004-01-01DOI: 10.1109/ICIMW.2004.1422123
V. Apletalin, Y. Kazantsev, V. Solosin, A. Zubov
A new technique is proposed to determine the permittivity and permeability of planar samples at millimeter wavelengths. The values of /spl epsiv/ and /spl mu/ are determined from the measurement of power reflected from the system planar specimen + metallic reflector for various positions of the reflector. The technique is realized using the precise quasioptical reflectometer.
{"title":"A new technique for permittivity and permeability measurements at millimeter waves","authors":"V. Apletalin, Y. Kazantsev, V. Solosin, A. Zubov","doi":"10.1109/ICIMW.2004.1422123","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422123","url":null,"abstract":"A new technique is proposed to determine the permittivity and permeability of planar samples at millimeter wavelengths. The values of /spl epsiv/ and /spl mu/ are determined from the measurement of power reflected from the system planar specimen + metallic reflector for various positions of the reflector. The technique is realized using the precise quasioptical reflectometer.","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":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81460907","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 : 2004-01-01DOI: 10.1109/ICIMW.2004.1422214
J. Heritage, A. Vlieks, C. DeStefano, W. Frederick, G. Caryotakis, N. Luhmann, D. Martin, E. Landahl
A compact source of monochromatic ultrashort X-ray pulses tunable in the 10 to 85 keV range is obtained from Compton scattering of intense sub-picosecond optical pulses with relativistic electron bunches. Unlike conventional large National Laboratory scale synchrotron radiation sources, the relativistic Compton device utilizes compact vacuum components including a single X-band klystron, a 5.5 cell photoinjector, and a 1.05-meter, high-gradient linear accelerator. Optical radiation is generated by a tabletop synchronized titanium:sapphire femtosecond laser oscillator and amplifier system. Our source holds great potential as a compact probe of inner shell bound electrons in heavy atoms for medical diagnostics and therapeutics, as well as for studies of fundamental atomic-scale physics.
{"title":"X-band photoinjector/high gradient accelerator based light source","authors":"J. Heritage, A. Vlieks, C. DeStefano, W. Frederick, G. Caryotakis, N. Luhmann, D. Martin, E. Landahl","doi":"10.1109/ICIMW.2004.1422214","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422214","url":null,"abstract":"A compact source of monochromatic ultrashort X-ray pulses tunable in the 10 to 85 keV range is obtained from Compton scattering of intense sub-picosecond optical pulses with relativistic electron bunches. Unlike conventional large National Laboratory scale synchrotron radiation sources, the relativistic Compton device utilizes compact vacuum components including a single X-band klystron, a 5.5 cell photoinjector, and a 1.05-meter, high-gradient linear accelerator. Optical radiation is generated by a tabletop synchronized titanium:sapphire femtosecond laser oscillator and amplifier system. Our source holds great potential as a compact probe of inner shell bound electrons in heavy atoms for medical diagnostics and therapeutics, as well as for studies of fundamental atomic-scale physics.","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":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82294375","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 : 2004-01-01DOI: 10.1109/ICIMW.2004.1422186
H. Nakata, A. Yokoyama, T. Hatou, T. Ohyama, N. Tsubouchi, S. Pavlov, H. W. Heubers
We observed infrared photoconductivity in Ge:Te and THz laser emission from Si:P excited by a free electron laser (FEL) or CO/sub 2/ lasers. The emission intensity decreases with increasing photon energy of the FEL in the range of about 120 meV. Photoconductivity spectra of Ge:Te has LO phonon structures.
{"title":"Excitation spectroscopy of Si:P THz laser and infrared photoconductivity in Ge:Te","authors":"H. Nakata, A. Yokoyama, T. Hatou, T. Ohyama, N. Tsubouchi, S. Pavlov, H. W. Heubers","doi":"10.1109/ICIMW.2004.1422186","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422186","url":null,"abstract":"We observed infrared photoconductivity in Ge:Te and THz laser emission from Si:P excited by a free electron laser (FEL) or CO/sub 2/ lasers. The emission intensity decreases with increasing photon energy of the FEL in the range of about 120 meV. Photoconductivity spectra of Ge:Te has LO phonon structures.","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":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76334883","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 : 2004-01-01DOI: 10.1109/ICIMW.2004.1422153
V. Khaikin, S. R. Zhelenkov, S. V. Kaplya
A radio telescope control and diagnostics system which has met hard enough requirements to pointing, tracking and scanning of the Sun with a multibeam radio telescope in short mm band is described. Radio telescope pointing and tracking accuracy tested in solar observations are presented.
{"title":"Precision mm wave multibeam radio telescope - control and diagnostics system","authors":"V. Khaikin, S. R. Zhelenkov, S. V. Kaplya","doi":"10.1109/ICIMW.2004.1422153","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422153","url":null,"abstract":"A radio telescope control and diagnostics system which has met hard enough requirements to pointing, tracking and scanning of the Sun with a multibeam radio telescope in short mm band is described. Radio telescope pointing and tracking accuracy tested in solar observations are 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":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76534079","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 : 2004-01-01DOI: 10.1109/ICIMW.2004.1422253
J. Thomson, A. Phelps, A. Cross, W. He, E. G. Rafferty, K. Ronald, C. Whyte, A. Young
Gyro-TWA (gyro-travelling wave amplifier) experiments are being undertaken employing a novel helically corrugated waveguide. Numerical and experimental techniques for determination of the waveguide dispersion characteristics are presented. A helically corrugated interaction structure designed and optimized for use with a novel cusp gun in a gyro-amplifier is discussed.
{"title":"High power microwave amplification using a novel fast wave gyro-TWA","authors":"J. Thomson, A. Phelps, A. Cross, W. He, E. G. Rafferty, K. Ronald, C. Whyte, A. Young","doi":"10.1109/ICIMW.2004.1422253","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422253","url":null,"abstract":"Gyro-TWA (gyro-travelling wave amplifier) experiments are being undertaken employing a novel helically corrugated waveguide. Numerical and experimental techniques for determination of the waveguide dispersion characteristics are presented. A helically corrugated interaction structure designed and optimized for use with a novel cusp gun in a gyro-amplifier is discussed.","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":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76031078","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 : 2004-01-01DOI: 10.1109/ICIMW.2004.1422079
M. Schwarz, B. Gunther, H. Richter, K. Rosner, H. Hubers
To date optically pumped gas lasers are used as local oscillators in heterodyne receivers at frequencies above 2 THz. In this report we describe the design and performance of a compact 1-5 THz gas laser which is operated in a heterodyne receiver aboard of SOFIA, the Stratospheric Observatory for Infrared Astronomy.
{"title":"Compact, optically pumped THz gas laser for SOFIA","authors":"M. Schwarz, B. Gunther, H. Richter, K. Rosner, H. Hubers","doi":"10.1109/ICIMW.2004.1422079","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422079","url":null,"abstract":"To date optically pumped gas lasers are used as local oscillators in heterodyne receivers at frequencies above 2 THz. In this report we describe the design and performance of a compact 1-5 THz gas laser which is operated in a heterodyne receiver aboard of SOFIA, the Stratospheric Observatory for Infrared Astronomy.","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":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88337648","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 : 2004-01-01DOI: 10.1109/ICIMW.2004.1422179
Masaya Nagai, Shingo Saito, Hideyuki Ohtake, T. Bessho, T. Sugiura, T. Hirosumi, M. Yoshida, Koichiro Tanaka
We demonstrate the generation and detection of a terahertz wave by non-resonant electro-optical processes with femtosecond 1.56 /spl mu/m laser pulses. Using a 0.5 mm-thick [110]-oriented GaAs wafer for optical rectification and electro-optical modulation, we achieve spectral sensitivity up to 3 THz. For high net efficiency of nonlinear process, it is important to evaluate the phase matching condition in electro-optical crystals.
{"title":"Generation and detection of terahertz radiation by non-resonant nonlinear process in GaAs using 1.56 /spl mu/m fiber laser pulses","authors":"Masaya Nagai, Shingo Saito, Hideyuki Ohtake, T. Bessho, T. Sugiura, T. Hirosumi, M. Yoshida, Koichiro Tanaka","doi":"10.1109/ICIMW.2004.1422179","DOIUrl":"https://doi.org/10.1109/ICIMW.2004.1422179","url":null,"abstract":"We demonstrate the generation and detection of a terahertz wave by non-resonant electro-optical processes with femtosecond 1.56 /spl mu/m laser pulses. Using a 0.5 mm-thick [110]-oriented GaAs wafer for optical rectification and electro-optical modulation, we achieve spectral sensitivity up to 3 THz. For high net efficiency of nonlinear process, it is important to evaluate the phase matching condition in electro-optical crystals.","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":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82720666","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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