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Gao, J.R. (author), de Graaf, C. (author), Caro, J. (author), Radelaar, S. (author), Offenberg, M. (author), Lauer, V. (author), Singleton, J. (author), Janssen, T.J.B.M. (author), Perenboom, J.A.A.J. (author)
journal article 1990
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Gao, J. (author)
doctoral thesis 1991
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Gao, J.R. (author), de Graaf, C. (author), Schüssler, A.S. (author), Caro, J. (author), Radelaar, S. (author), Heyers, K. (author)
journal article 1992
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Wilms Fleet, D. (author), Gao, J.R. (author), Klapwijk, T.M. (author), de Eorte, P.A.J. (author)
journal article 2001
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Ganzevles, W.F.M. (author), Yagoubov, P. (author), Gao, J.R. (author), Klapwijk, T.M. (author), de Korte, P.A.J. (author)
journal article 2001
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Iosad, N.N. (author), Roddatis, V.V. (author), Polyakov, S.N. (author), Varlashkin, A.V. (author), Jackson, B.D. (author), Dmitriev, P.N. (author), Gao, J.R. (author), Klapwijk, T.M. (author)
journal article 2001
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Wang, X.W. (author), Gao, F.L. (author), Zhang, X.M. (author), Ruan, B.Q. (author)
Water resources contribute greatly to human well being, both directly and indirectly. Water resources are irreplaceable natural resources, and are limited. However, due to a growing population and related economic development, the water demand from urban, industry and agriculture has increased dramatically. Water shortage has become one of the...
report 2002
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Baselmans, J.J.A. (author), Hajenius, M. (author), Gao, J.R. (author), Klapwijk, T.M. (author), De Korte, P.A.J. (author), Voronov, B. (author), Gol'tsman, G. (author)
We demonstrate that the performance of NbN lattice cooled hot electron bolometer mixers depends strongly on the interface quality between the bolometer and the contact structure. We show experimentally that both the receiver noise temperature and the gain bandwidth can be improved by more than a factor of 2 by cleaning the interface and adding...
journal article 2004
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Baselmans, J. (author), Hajenius, M. (author), Gao, J. (author), De Korte, P. (author), Klapwijk, T. (author), Voronov, B. (author), Gol'tsman, G. (author)
NbN hot electron bolometer (HEB) mixers are at this moment the best heterodyne detectors for frequencies above 1 THz. However, the fabrication procedure of these devices is such that the quality of the interface between the NbN superconducting film and the contact structure is not under good control. This results in a contact resistance between...
conference paper 2004
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Klapwijk, T.M. (author), Barends, R. (author), Gao, J.R. (author), Hajenius, M. (author), Baselmans, J.J.A. (author)
Improved and reproducible heterodyne mixing (noise temperatures of 950 K at 2.5 THz) has been realized with NbN based hot-electron superconducting devices with low contact resistances. A distributed temperature numerical model of the NbN bridge, based on a local electron and a phonon temperature, has been used to understand the physical...
conference paper 2004
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Baselmans, J.J.A. (author), Baryshev, A. (author), Reker, S.F. (author), Hajenius, M. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Vachtomin, Y. (author), Maslennikov, S. (author), Antipov, S. (author), Voronov, B. (author), Gol'tsman, G. (author)
We measure the direct detection effect in a small volume (0.15??m×1??m×3.5?nm) quasioptical NbN phonon cooled hot electron bolometer mixer at 1.6?THz. We find that the small signal sensitivity of the receiver is underestimated by 35% due to the direct detection effect and that the optimal operating point is shifted to higher bias voltages when...
journal article 2005
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Gao, J.R. (author), Hovenier, J.N. (author), Yang, Z.Q. (author), Baselmans, J.J.A. (author), Baryshev, A. (author), Hajenius, M. (author), Klapwijk, T.M. (author), Adam, A.J.L. (author), Klaassen, T.O. (author), Williams, B.S. (author), Kumar, S. (author), Hu, Q. (author), Reno, J.L. (author)
We report the first demonstration of an all solid-state heterodyne receiver that can be used for high-resolution spectroscopy above 2?THz suitable for space-based observatories. The receiver uses a NbN superconducting hot-electron bolometer as mixer and a quantum cascade laser operating at 2.8?THz as local oscillator. We measure a double...
journal article 2005
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Barends, R. (author), Hajenius, M. (author), Gao, J.R. (author), Klapwijk, T.M. (author)
We present a description of the current-voltage characteristics of hot electron bolometers in terms of the current-dependent intrinsic resistive transition of NbN films. We find that, by including this current dependence, we can correctly predict the complete current-voltage characteristics, showing excellent agreement with measurements for both...
journal article 2005
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Yang, Z.Q. (author), Hajenius, M. (author), Baselmans, J.J.A. (author), Gao, J.R. (author), Voronov, B. (author), Gol'tsman, G.N. (author)
journal article 2006
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Orlova, E.E. (author), Hovenier, J.N. (author), Klaassen, T.O. (author), Kasalynas, I. (author), Adam, A.J.L. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Williams, B.S. (author), Kumar, S. (author), Hu, Q. (author), Reno, J.L. (author)
journal article 2006
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Adam, A.J.L. (author), Kašalynas, I. (author), Hovenier, J.N. (author), Klaassen, T.O. (author), Gao, J.R. (author), Orlova, E.E. (author), Williams, B.S. (author), Kumar, S. (author), Hu, Q. (author), Reno, J.L. (author)
The need to reach single-mode lasing and minimize at the same time the electrical dissipation of cryogenically operated terahertz quantum cascade lasers may result in small and subwavelength cavity dimensions. To assess the influence of such dimensions on the shape of the laser emission, we have measured the beam pattern of two metal-metal...
journal article 2006
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Baryshev, A. (author), Hovenier, J.N. (author), Adam, A.J.L. (author), Kašalynas, I. (author), Gao, J.R. (author), Klaassen, T.O. (author), Williams, B.S. (author), Kumar, S. (author), Hu, Q. (author), Reno, J.L. (author)
We have studied the phase locking and spectral linewidth of an ? 2.7?THz quantum cascade laser by mixing its two lateral lasing modes. The beat signal at about 8?GHz is compared with a microwave reference by applying conventional phase lock loop circuitry with feedback to the laser bias current. Phase locking has been demonstrated, resulting in...
journal article 2006
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Kooi, J.W. (author), Baselmans, J.J.A. (author), Baryshev, A. (author), Schieder, R. (author), Hajenius, M. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Voronov, B. (author), Gol'tsman, G. (author)
In this paper we discuss the stability of heterodyne terahertz receivers based on small volume NbN phonon cooled hot electron bolometers (HEBs). The stability of these receivers can be broken down in two parts: the intrinsic stability of the HEB mixer and the stability of the local oscillator (LO) signal injection scheme. Measurements show that...
journal article 2006
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Hajenius, M. (author), Baselmans, J.J.A. (author), Baryshev, A. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Kooi, J.W. (author), Jellema, W. (author), Yang, Z.Q. (author)
We present a complete experimental characterization of a quasioptical twin-slot antenna coupled small area (1.0×0.15??m2) NbN hot electron bolometer (HEB) mixer compatible with currently available solid state tunable local oscillator (LO) sources. The required LO power absorbed in the HEB is analyzed in detail and equals only 25?nW. Due to the...
journal article 2006
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Baselmans, J.J.A. (author), Baryshev, A. (author), Reker, S.F. (author), Hajenius, M. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Voronov, B. (author), Gol'tsman, G. (author)
We present a detailed experimental study of the direct detection effect in a small volume (0.15??m×1??m×3.5?nm) quasioptical NbN phonon cooled hot electron bolometer mixer at 673?GHz. We find that the small signal noise temperature, relevant for an astronomical observation, is 20% lower than the noise temperature obtained using 300 and 77?K...
journal article 2006
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