Pub Date : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327872
J. Neu, M. Rahm
We demonstrate a spatially resolved method to measure carrier lifetimes and carrier distributions based on optical pump - terahertz probe spectroscopy. The pump-probe delay range spans from 600 ps to 200 μs. The spatial resolution is sub-wavelength being better than 50 μm (<; λ<;sub>center<;/sub>/6 at 1THz).
{"title":"Time-domain optical pump — Terahertz probe spectroscopic imager for carrier lifetime measurements in the pico- to microsecond regime","authors":"J. Neu, M. Rahm","doi":"10.1109/IRMMW-THZ.2015.7327872","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327872","url":null,"abstract":"We demonstrate a spatially resolved method to measure carrier lifetimes and carrier distributions based on optical pump - terahertz probe spectroscopy. The pump-probe delay range spans from 600 ps to 200 μs. The spatial resolution is sub-wavelength being better than 50 μm (<; λ<;sub>center<;/sub>/6 at 1THz).","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"37 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75273560","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327847
J. Hummelt, S. Jawla, E. Kowalski, M. Shapiro, R. Temkin
High power sources of coherent radiation, producing Watts to tens of Watts of average power, are needed for applications in the millimeter wave and THz regimes. Overmoded traveling wave tubes offer the possibility of meeting these requirements in rugged and simple to fabricate devices. Results on a 94 GHz overmoded TWT confirm the viability of this approach. Designs for a PBG amplifier operating at 250 GHz, based on the successful 94 GHz TWT, are described.
{"title":"Overmoded traveling wave tubes for MM and THz applications","authors":"J. Hummelt, S. Jawla, E. Kowalski, M. Shapiro, R. Temkin","doi":"10.1109/IRMMW-THZ.2015.7327847","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327847","url":null,"abstract":"High power sources of coherent radiation, producing Watts to tens of Watts of average power, are needed for applications in the millimeter wave and THz regimes. Overmoded traveling wave tubes offer the possibility of meeting these requirements in rugged and simple to fabricate devices. Results on a 94 GHz overmoded TWT confirm the viability of this approach. Designs for a PBG amplifier operating at 250 GHz, based on the successful 94 GHz TWT, are described.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"51 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73219321","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327817
S. Hisatake, Hai Huy Nguyen Pham, T. Nagatsuma
Wavefront conversion by a metal hole array (MHA) has been experimentally observed via a visualization of the continuous-wave terahertz (THz) field. At the resonant frequency of the MHA, curved wavefront of the THz wave (125 GHz) emitted from a horn antenna has been converted to a plane wavefront. Near field visualization at the MHA surface (transmission side) revealed that the field re-emitted from the MHA oscillates in phase. We experimentally confirmed that the MHA acts as a planar THz wave collimator.
{"title":"Direct observation of terahertz wavefront converted by a metal hole array","authors":"S. Hisatake, Hai Huy Nguyen Pham, T. Nagatsuma","doi":"10.1109/IRMMW-THZ.2015.7327817","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327817","url":null,"abstract":"Wavefront conversion by a metal hole array (MHA) has been experimentally observed via a visualization of the continuous-wave terahertz (THz) field. At the resonant frequency of the MHA, curved wavefront of the THz wave (125 GHz) emitted from a horn antenna has been converted to a plane wavefront. Near field visualization at the MHA surface (transmission side) revealed that the field re-emitted from the MHA oscillates in phase. We experimentally confirmed that the MHA acts as a planar THz wave collimator.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"29 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73580176","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327441
Yanqing Gao, Zhiming Huang, Y. Hou, Jing Wu, Wei Zhou, C. Ouyang, J. Chu
High quality Mn1.56Co0.96Ni0.48O4 films with different layers have been prepared on Pt//Ti/SiO2/Si substrate. Infrared optical properties of the films have been investigated using infrared spectroscopic ellipsometry. The optical constants have been obtained by fitting the measured ellipsometric parameter data with classical infrared model.
{"title":"Infrared ellipsometric spectroscopy of Mn1.56Co0.96Ni0.48O4 thin films with different layers","authors":"Yanqing Gao, Zhiming Huang, Y. Hou, Jing Wu, Wei Zhou, C. Ouyang, J. Chu","doi":"10.1109/IRMMW-THZ.2015.7327441","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327441","url":null,"abstract":"High quality Mn<sub>1.56</sub>Co<sub>0.96</sub>Ni<sub>0.48</sub>O<sub>4</sub> films with different layers have been prepared on Pt//Ti/SiO<sub>2</sub>/Si substrate. Infrared optical properties of the films have been investigated using infrared spectroscopic ellipsometry. The optical constants have been obtained by fitting the measured ellipsometric parameter data with classical infrared model.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"16 4 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75480097","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327408
R. Dietz, B. Globisch, H. Roehle, T. Gobel, M. Schell
We present an all fiber coupled terahertz (THz) time domain spectroscopy (THz-TDS) system operating at 1.5 μm wavelength with very high dynamic range. The broadband THz radiation is generated by a high mobility InGaAs/InAlAs heterostructure photoconductive emitter. For the detection a low temperature grown (LTG) Be-doped InGaAs/InAlAs heterostructure is employed. Both, detector and emitter, are packaged into fiber-coupled housings. The system reaches a dynamic range in excess of 100 dB and a spectral bandwidth of 6.5 THz.
{"title":"Fiber coupled terahertz time domain spectroscopy system based on InGaAs/InAlAs photoconductors with 100 dB dynamic range","authors":"R. Dietz, B. Globisch, H. Roehle, T. Gobel, M. Schell","doi":"10.1109/IRMMW-THZ.2015.7327408","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327408","url":null,"abstract":"We present an all fiber coupled terahertz (THz) time domain spectroscopy (THz-TDS) system operating at 1.5 μm wavelength with very high dynamic range. The broadband THz radiation is generated by a high mobility InGaAs/InAlAs heterostructure photoconductive emitter. For the detection a low temperature grown (LTG) Be-doped InGaAs/InAlAs heterostructure is employed. Both, detector and emitter, are packaged into fiber-coupled housings. The system reaches a dynamic range in excess of 100 dB and a spectral bandwidth of 6.5 THz.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"14 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78435397","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327646
I. Zotova, N. Ginzburg, A. Golovanov, M. Yalandin, V. Rostov
Recently coherent summation of several SR pulses generated in parallel channels has been demonstrated in X- and Ka wavelength bands. This possibility is caused by picosecond stability of explosive emission from a cold cathode and strong correlation of phase of the SR pulses with respect to the leading edge of the electron bunch. In fact stimulated SR emission is initiated by spontaneous mission from bunch leading edges. In report we describe results of recent experiments and develop a theoretical model which covers both spontaneous and stimulated Cherenkov emission.
{"title":"Generation of cherenkov superradiant pulses with correlated phases defined by sharp edges of high-current electron bunches","authors":"I. Zotova, N. Ginzburg, A. Golovanov, M. Yalandin, V. Rostov","doi":"10.1109/IRMMW-THZ.2015.7327646","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327646","url":null,"abstract":"Recently coherent summation of several SR pulses generated in parallel channels has been demonstrated in X- and Ka wavelength bands. This possibility is caused by picosecond stability of explosive emission from a cold cathode and strong correlation of phase of the SR pulses with respect to the leading edge of the electron bunch. In fact stimulated SR emission is initiated by spontaneous mission from bunch leading edges. In report we describe results of recent experiments and develop a theoretical model which covers both spontaneous and stimulated Cherenkov emission.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"47 2 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77494224","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327525
Z. Jin, H. Zhuo, J. Shin, N. Yugami, M. Yu, Z. Sheng, R. Kodama
Ultra-intense radiation in the terahertz (THz) regime emitted from the rear side of laser-irradiated solid target is experimentally investigated using a 20 TW fs laser system. The THz radiation emitted in a conical angle around 45 degrees is of radially polarized and has its duration of tens of ps. The waveform, angular distribution, polarization and laser intensity dependence of the observed radiation are in good agreement with those predicted for the radiation from deceleration of >sub-MeV electrons passing through the sheath electric field behind the target.
{"title":"Ultra-intense laser-driven target normal sheath radiation in the terahertz region","authors":"Z. Jin, H. Zhuo, J. Shin, N. Yugami, M. Yu, Z. Sheng, R. Kodama","doi":"10.1109/IRMMW-THZ.2015.7327525","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327525","url":null,"abstract":"Ultra-intense radiation in the terahertz (THz) regime emitted from the rear side of laser-irradiated solid target is experimentally investigated using a 20 TW fs laser system. The THz radiation emitted in a conical angle around 45 degrees is of radially polarized and has its duration of tens of ps. The waveform, angular distribution, polarization and laser intensity dependence of the observed radiation are in good agreement with those predicted for the radiation from deceleration of >sub-MeV electrons passing through the sheath electric field behind the target.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"144 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80420307","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327674
J. Mabon, R. Lewis
We extend a mathematical investigation of the noise in THz electro-optic detectors by considering the non-ideal properties of beam splitters in addition to non-ideal polarisers. It is found that the non-ideal properties of typical beam splitters can result in an unwanted noise floor in certain detectors.
{"title":"Effect of non-ideal beamsplitters in THz electro-optic detectors","authors":"J. Mabon, R. Lewis","doi":"10.1109/IRMMW-THZ.2015.7327674","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327674","url":null,"abstract":"We extend a mathematical investigation of the noise in THz electro-optic detectors by considering the non-ideal properties of beam splitters in addition to non-ideal polarisers. It is found that the non-ideal properties of typical beam splitters can result in an unwanted noise floor in certain detectors.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"28 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81544941","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327692
S. Pavlov, N. Desmann, A. Pohl, N. Abrosimov, S. Winnerl, Otto Jacob, R. Zhukavin, D. V. Shengurov, V. V. Tsyplenkov, K. Kovalevsky, V. Shastin, H. Hubers
Summary form only given. A broad-band fast germanium detector based on unipolar and bipolar photoconductivity has been demonstrated. Typical response times are about 200 ps. Such short times are realized by using heavily doped and highly compensated germanium crystals.
{"title":"Picosecond VIS-FIR photoconductive germanium detector","authors":"S. Pavlov, N. Desmann, A. Pohl, N. Abrosimov, S. Winnerl, Otto Jacob, R. Zhukavin, D. V. Shengurov, V. V. Tsyplenkov, K. Kovalevsky, V. Shastin, H. Hubers","doi":"10.1109/IRMMW-THZ.2015.7327692","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327692","url":null,"abstract":"Summary form only given. A broad-band fast germanium detector based on unipolar and bipolar photoconductivity has been demonstrated. Typical response times are about 200 ps. Such short times are realized by using heavily doped and highly compensated germanium crystals.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"32 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80799293","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327751
J. Molloy, M. Naftaly, Y. Andreev, K. Kokh, G. Lanskii, V. Svetlichnyi
High optical quality GaSe samples with faces parallel and orthogonal to the optical axis are manufactured. o-and e-wave dispersions are studied by THz time domain spectroscopy. New dispersion equations are designed that are suitable for application in the entire transparency range from the near IR through the mid-IR and further into the THz.
{"title":"Dispersion equations for the entire transparency range of GaSe","authors":"J. Molloy, M. Naftaly, Y. Andreev, K. Kokh, G. Lanskii, V. Svetlichnyi","doi":"10.1109/IRMMW-THZ.2015.7327751","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327751","url":null,"abstract":"High optical quality GaSe samples with faces parallel and orthogonal to the optical axis are manufactured. o-and e-wave dispersions are studied by THz time domain spectroscopy. New dispersion equations are designed that are suitable for application in the entire transparency range from the near IR through the mid-IR and further into the THz.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"57 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72821148","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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