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Author | Gao, J. R.; Hovenier, J. N.; Yang, Z. Q.; Baselmans, J. J. A.; Baryshev, A.; Hajenius, M.; Klapwijk, T. M.; Adam, A. J. L.; Klaassen, T. O.; Williams, B. S.; Kumar, S.; Hu, Q.; Reno, J. L. | ||||
Title | Terahertz heterodyne receiver based on a quantum cascade laser and a superconducting bolometer | Type | Journal Article | ||
Year | 2005 | Publication | Appl. Phys. Lett. | Abbreviated Journal | Appl. Phys. Lett. |
Volume | 86 | Issue | Pages | 244104 (1 to 3) | |
Keywords | HEB, QCL | ||||
Abstract | We report the first demonstration of an all solid-stateheterodyne receiver that can be used for high-resolution spectroscopy above 2THz suitable for space-based observatories. The receiver uses a NbN superconducting hot-electron bolometer as mixer and a quantum cascade laser operating at 2.8THz as local oscillator. We measure a double sideband receiver noise temperature of 1400K at 2.8THz and 4.2K, and find that the free-running QCL has sufficient power stability for a practical receiver, demonstrating an unprecedented combination of sensitivity and stability. | ||||
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Notes | Approved | no | |||
Call Number | Serial | 905 | |||
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Author | Bueno, J.; Coumou, P. C. J. J.; Zheng, G.; de Visser, P. J.; Klapwijk, T. M.; Driessen, E. F. C.; Doyle, S.; Baselmans, J. J. A | ||||
Title | Anomalous response of superconducting titanium nitride resonators to terahertz radiation | Type | Journal Article | ||
Year | 2014 | Publication | Appl. Phys. Lett. | Abbreviated Journal | |
Volume | 105 | Issue | Pages | 192601 (1 to 5) | |
Keywords | KID, TiN, NEP, disordered superconductors, inhomogeneous state | ||||
Abstract | We present an experimental study of kinetic inductance detectors (KIDs) fabricated of atomic layer deposited TiN films and characterized at radiation frequencies of 350 GHz. The responsivity to radiation is measured and found to increase with the increase in radiation powers, opposite to what is expected from theory and observed for hybrid niobium titanium nitride/aluminium (NbTiN/Al) and all-aluminium (all-Al) KIDs. The noise is found to be independent of the level of the radiation power. The noise equivalent power improves with higher radiation powers, also opposite to what is observed and well understood for hybrid NbTiN/Al and all-Al KIDs. We suggest that an inhomogeneous state of these disordered superconductors should be used to explain these observations. | ||||
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Notes | Approved | no | |||
Call Number | Serial | 1068 | |||
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Author | Baselmans, J. J. A.; Baryshev, A.; Reker, S. F.; Hajenius, M.; Gao, J. R.; Klapwijk, T. M.; Vahtomin, Yu.; Maslennikov, S.; Antipov, S.; Voronov, B.; Gol'tsman, G. | ||||
Title | Direct detection effect in small volume hot electron bolometer mixers | Type | Journal Article | ||
Year | 2005 | Publication | Appl. Phys. Lett. | Abbreviated Journal | Appl. Phys. Lett. |
Volume | 86 | Issue | 16 | Pages | 163503 (1 to 3) |
Keywords | HEB, mixer, direct detection effect | ||||
Abstract | We measure the direct detection effect in a small volume (0.15μm×1μm×3.5nm)(0.15μm×1μm×3.5nm) quasioptical NbN phonon cooled hot electronbolometermixer at 1.6THz1.6THz. 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 using calibration loads of 300K300K and 77K77K. Using a 200GHz200GHzbandpass filter at 4.2K4.2K the direct detection effect virtually disappears. This has important implications for the calibration procedure of these receivers in real telescope systems. | ||||
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Notes | Approved | no | |||
Call Number | Serial | 377 | |||
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Author | Baselmans, J. J. A.; Baryshev, A.; Reker, S. F.; Hajenius, M.; Gao, J. R.; Klapwijk, T. M.; Voronov, B.; Gol’tsman, G. | ||||
Title | Influence of the direct response on the heterodyne sensitivity of hot electron bolometer mixers | Type | Journal Article | ||
Year | 2006 | Publication | J. Appl. Phys. | Abbreviated Journal | J. Appl. Phys. |
Volume | 100 | Issue | 8 | Pages | 084510 (1 to 7) |
Keywords | NbN HEB mixers | ||||
Abstract | We present a detailed experimental study of the direct detection effect in a small volume (0.15μm×1μm×3.5nm) quasioptical NbN phonon cooled hot electron bolometer mixer at 673GHz. We find that the small signal noise temperature, relevant for an astronomical observation, is 20% lower than the noise temperature obtained using 300 and 77K calibration loads. In a separate set of experiments we show that the direct detection effect is caused by a combination of bias current reduction when switching from the 77 to the 300K load in combination with the bias current dependence of the receiver gain. The bias current dependence of the receiver gain is shown to be mainly caused by the current dependence of the mixer gain. |
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ISSN | 0021-8979 | ISBN | Medium | ||
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Notes | Approved | no | |||
Call Number | Serial | 1442 | |||
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Author | Hajenius, M.; Baselmans, J. J. A.; Baryshev, A.; Gao, J. R.; Klapwijk, T. M.; Kooi, J. W.; Jellema, W.; Yang, Z. Q. | ||||
Title | Full characterization and analysis of a terahertz heterodyne receiver based on a NbN hot electron bolometer | Type | Journal Article | ||
Year | 2006 | Publication | J. Appl. Phys. | Abbreviated Journal | |
Volume | 100 | Issue | 7 | Pages | 074507 |
Keywords | HEB | ||||
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ISSN | 0021-8979 | ISBN | Medium | ||
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Notes | Approved | no | |||
Call Number | RPLAB @ s @ | Serial | 385 | ||
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Author | Kooi, J. W.; Baselmans, J. J. A.; Baryshev, A.; Schieder, R.; Hajenius, M.; Gao, J.R.; Klapwijk, T. M.; Voronov, B.; Gol’tsman, G. | ||||
Title | Stability of heterodyne terahertz receivers | Type | Journal Article | ||
Year | 2006 | Publication | J. Appl. Phys. | Abbreviated Journal | J. Appl. Phys. |
Volume | 100 | Issue | 6 | Pages | 064904 (1 to 9) |
Keywords | NbN HEB mixers | ||||
Abstract | 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 the HEB mixer stability is limited by gain fluctuations with a 1∕f spectral distribution. In a 60MHz noise bandwidth this results in an Allan variance stability time of ∼0.3s. Measurement of the spectroscopic Allan variance between two intermediate frequency (IF) channels results in a much longer Allan variance stability time, i.e., 3s between a 2.5 and a 4.7GHz channel, and even longer for more closely spaced channels. This implies that the HEB mixer 1∕f noise is strongly correlated across the IF band and that the correlation gets stronger the closer the IF channels are spaced. In the second part of the paper we discuss atmospheric and mechanical system stability requirements on the LO-mixer cavity path length. We calculate the mixer output noise fluctuations as a result of small perturbations of the LO-mixer standing wave, and find very stringent mechanical and atmospheric tolerance requirements for receivers operating at terahertz frequencies. | ||||
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ISSN | 0021-8979 | ISBN | Medium | ||
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Notes | Approved | no | |||
Call Number | Serial | 1444 | |||
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Author | Kooi, J. W.; Baselmans, J. J. A.; Hajenius, M.; Gao, J. R.; Klapwijk, T. M.; Dieleman, P.; Baryshev, A.; de Lange, G. | ||||
Title | IF impedance and mixer gain of NbN hot electron bolometers | Type | Journal Article | ||
Year | 2007 | Publication | J. Appl. Phys. | Abbreviated Journal | |
Volume | 101 | Issue | 4 | Pages | 044511 |
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ISSN | 0021-8979 | ISBN | Medium | ||
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Notes | Approved | no | |||
Call Number | RPLAB @ s @ | Serial | 445 | ||
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Author | Floet, D. Wilms; Baselmans, J. J. A.; Klapwijk, T. M.; Gao, J. R. | ||||
Title | Resistive transition of niobium superconducting hot-electron bolometer mixers | Type | Journal Article | ||
Year | 1998 | Publication | Applied Physics Letters | Abbreviated Journal | Appl. Phys. Lett. |
Volume | 73 | Issue | 19 | Pages | 2826 |
Keywords | HEB | ||||
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ISSN | 0003-6951 | ISBN | Medium | ||
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Notes | Approved | no | |||
Call Number | Serial | 543 | |||
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Author | Baselmans, J. J. A.; Hajenius, M.; Gao, J. R.; Klapwijk, T. M.; de Korte, P. A. J.; Voronov, B.; Gol'tsman, G. | ||||
Title | Doubling of sensitivity and bandwidth in phonon cooled hot electron bolometer mixers | Type | Journal Article | ||
Year | 2004 | Publication | Appl. Phys. Lett. | Abbreviated Journal | Appl. Phys. Lett. |
Volume | 84 | Issue | 11 | Pages | 1958-1960 |
Keywords | NbN HEB mixers | ||||
Abstract | 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 an additional superconducting interlayer to the contact pad. Using this we obtain a double sideband receiver noise temperature TN,DSB=950 K at 2.5 THz and 4.3 K, uncorrected for losses in the optics. At the same bias point, we obtain an IF gain bandwidth of 6 GHz. |
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Notes | Approved | no | |||
Call Number | Serial | 352 | |||
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Author | Hajenius, M.; Barends, R.; Gao, J. R.; Klapwijk, T. M.; Baselmans, J. J. A.; Baryshev, A.; Voronov, B.; Gol'tsman, G. | ||||
Title | Local resistivity and the current-voltage characteristics of hot electron bolometer mixers | Type | Journal Article | ||
Year | 2005 | Publication | IEEE Trans. Appl. Supercond. | Abbreviated Journal | IEEE Trans. Appl. Supercond. |
Volume | 15 | Issue | 2 | Pages | 495-498 |
Keywords | HEB mixer distributed model, HEB distributed model, distributed HEB model | ||||
Abstract | Hot-electron bolometer devices, used successfully in low noise heterodyne mixing at frequencies up to 2.5 THz, have been analyzed. A distributed temperature numerical model of the NbN bridge, based on a local electron and a phonon temperature, is used to model pumped IV curves and understand the physical conditions during the mixing process. We argue that the mixing is predominantly due to the strongly temperature dependent local resistivity of the NbN. Experimentally we identify the origins of different transition temperatures in a real HEB device, suggesting the importance of the intrinsic resistive transition of the superconducting bridge in the modeling. | ||||
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ISSN | 1051-8223 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | Serial | 980 | |||
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Author | Baselmans, J. J. A.; Hajenius, M.; Gao, J. R.; Baryshev, A.; Kooi, J.; Klapwijk, T. M.; Voronov, B.; de Korte, P.; Gol'tsman, G. | ||||
Title | NbN hot electron bolometer mixers: sensitivity, LO power, direct detection and stability | Type | Journal Article | ||
Year | 2005 | Publication | IEEE Trans. Appl. Supercond. | Abbreviated Journal | IEEE Trans. Appl. Supercond. |
Volume | 15 | Issue | 2 | Pages | 484-489 |
Keywords | HEB mixers, direct detection effect, stability, Allan variance | ||||
Abstract | 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. Both the receiver noise temperature and the gain bandwidth can be improved by a factor of 2 by cleaning the interface and adding an additional superconducting interlayer to the contact pad. Using this we obtain a double sideband receiver noise temperature of 950 K at 2.5 THz and 4.3 K, using a 0.4/spl times/4 /spl mu/m HEB mixer with a spiral antenna. At the same bias point, we obtain an IF gain bandwidth of 6 GHz. To comply with current demands on THz mixers for use in space based receivers we reduce the device size to 0.15/spl times/1 /spl mu/m and use a twin slot antenna. We report measurements of the noise temperature, LO power requirement, stability and the direct detection effect, using a mixer with a 1.6 THz twin slot antenna and a 1.462 THz solid state LO source with calibrated output power. | ||||
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ISSN | 1051-8223 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | Serial | 546 | |||
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Author | Baryshev, A.; Baselmans, J. J. A.; Reker, S. F.; Hajenius, M.; Gao, J. R.; Klapwijk, T. M.; Vachtomin, Yu.; Maslennikov, S.; Antipov, S.; Voronov, B.; Gol'tsman, G. | ||||
Title | Direct detection effect in hot electron bolometer mixers | Type | Abstract | ||
Year | 2005 | Publication | Proc. 16th Int. Symp. Space Terahertz Technol. | Abbreviated Journal | Proc. 16th Int. Symp. Space Terahertz Technol. |
Volume | Issue | Pages | 463-464 | ||
Keywords | NbN HEB mixers, effect of direct detection, direct detection effect | ||||
Abstract | NbN phonon cooled hot electron bolometer (HEB) mixers are currently the most sensitive heterodyne detectors at frequencies above 1.2 THz. They combine a good sensitivity (8-15 times the quantum limit), an IF bandwidth of the order of 4-6 GHz and a wide RF bandwidth from 0.7-5.2 THz. However, for use in a space based observatory, such as Herschel, it is of vital importance that the Local Oscillator (LO) power requirement of the mixer is compatible with the low output power of present day THz LO sources. This can be achieved by reducing the mixer volume and critical current. However, the large RF bandwidth and low LO power requirement of such a mixer result in a direct detection effect, characterized by a change in the bias current of the HEB when changing the RF signal from a black body load at 300 K to one at 77 K. As a result the measured sensitivity using a 300 K and 77 K calibration load differs significantly from the small signal sensitivity relevant for astronomical observations. In this article we describe a set of dedicated experiments to characterize the direct detection effect for a small volume quasi-optical NbN phonon cooled HEB mixer. We measure the direct detection effect in a small volume (0.15 μm · 1 μm · 3.5 nm) quasi- optical NbN phonon cooled HEB mixer at 1.6 THz. We found that the small signal sensitivity of the receiver is underestimated by approximately 35% due to the direct detection effect and that the optimal operating point is shifted to higher bias voltages when using calibration loads of 300 K and 77 K. Using a 200 GHz wide band-pass filter at the 4.2 K the direct detection effect virtually disappears. Heterodyne response measurements using water vapor absorption line in a gas cell confirms the existence and a magnitude of a direct detection effect. We also propose a theoretical explanation using uniform electron heating model. This direct detection effect has important implications for the calibration procedure of these receivers in real telescope systems. We are developing Nb HEBs for a large-format, diffusion-cooled hot electron bolometer (HEB) array submillimeter camera. The goal is to produce a 64 pixel array together with the University of Arizona to be used on the HHT on Mt Graham. It is designed to detect in the 850 GHz atmospheric window. We have fabricated Nb HEBs using a new angle- deposition process, which had previously produced high quality Nb-Au bilayer HEB devices at Yale. [1] We have characterized these devices using heterodyne mixing at ~30 GHz to compare to 345 GHz tests at the University of Arizona. We can also directly compare our Nb HEB mixers to SIS mixers in this same 345 GHz system. This allows us to rigorously calibrate the system’s losses and extract the mixer noise temperature in a well characterized mixer block, before undertaking the 850 GHz system. Here we give a report on the initial devices we have fabricated and characterized. * Department of Applied Physics, Yale University ** Department of Astronomy, University of Arizona [1] Applied Physics Letters 84, Number 8; p.1404-7, Feb 23 (2004) | ||||
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Call Number | Serial | 1475 | |||
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Author | Baselmans, J.; Kooi, J.; Baryshev, A.; Yang, Z. Q.; Hajenius, M.; Gao, J. R.; Klapwijk, T. M.; Voronov, B.; Gol’tsman, G. | ||||
Title | Full characterization of small volume NbN HEB mixers for space applications | Type | Conference Article | ||
Year | 2005 | Publication | Proc. 16th Int. Symp. Space Terahertz Technol. | Abbreviated Journal | Proc. 16th Int. Symp. Space Terahertz Technol. |
Volume | Issue | Pages | 457-462 | ||
Keywords | NbN HEB mixers | ||||
Abstract | NbN phonon cooled HEB’s are one of the most promising bolometer mixer technologies for (near) future (space) applications. Their performance is usually quantified by mea- suring the receiver noise temperature at a given IF frequency, usually around 1 – 2 GHz. However, for any real applications it is vital that one fully knows all the relevant properties of the mixer, including LO power, stability, direct detection, gain bandwidth and noise bandwidth, not only the noise temperature at low IF frequencies. To this aim we have measured all these parameters at the optimal operating point of one single, small volume quasioptical NbN HEB mixer. We find a minimum noise temperature of 900 K at 1.46 THz. We observe a direct detection effect indicated by a change in bias current when changing from a 300 K hot load to a 77 K cold load. Due to this effect we overestimate the noise temperature by about 22% using a 300 K hot load and a 77 K cold load. The LO power needed to reach the optimal operating point is 80 nW at the receiver lens front, 59 nW inside the NbN bridge. However, using the isothermal technique we find a power absorbed in the NbN bridge of 25 nW, a difference of about a factor 2. We obtain a gain bandwidth of 2.3 GHz and a noise bandwidth of 4 GHz. The system Allan time is about 1 sec. in a 50 MHz spectral bandwidth and a deviation from white noise integration (governed by the radiometer equation) occurs at 0.2 sec., which implies a maximum integration time of a few seconds in a 1 MHz bandwidth spectrometer. | ||||
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Publisher | Place of Publication | Göteborg, Sweden | Editor | ||
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Notes | Approved | no | |||
Call Number | Serial | 363 | |||
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Author | Hajenius, M.; Baselmans, J. J. A.; Gao, J. R.; Klapwijk, T. M.; de Korte, P. A. J.; Voronov, B.; Gol’tsman, G. | ||||
Title | Improved NbN phonon cooled hot electron bolometer mixers | Type | Conference Article | ||
Year | 2003 | Publication | Proc. 14th Int. Symp. Space Terahertz Technol. | Abbreviated Journal | Proc. 14th Int. Symp. Space Terahertz Technol. |
Volume | Issue | Pages | 413-423 | ||
Keywords | NbN HEB mixers | ||||
Abstract | NbN phonon-cooled hot electron bolometer mixers (HEBs) have been realized with negligible contact resistance to Au pads. By adding either a 5 nm Nb or a 10 nm NbTiN layer between the Au and NbN, to preserve superconductivity in the NbN under the Au contact pad, superior noise temperatures have been obtained. Using DC I,V curves and resistive transitions in combination with process parameters we analyze the nature of these improved devices and determine interface transparencies. | ||||
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Publisher | Place of Publication | Tucson, USA | Editor | ||
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Notes | Approved | no | |||
Call Number | Serial | 337 | |||
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Author | Hajenius, M.; Yang, Z. Q.; Gao, J. R.; Baselmans, J. J. A.; Klapwijk, T. M.; Voronov, B.; Gol'tsman, G. | ||||
Title | Optimized sensitivity of NbN hot electron bolometer mixers by annealing | Type | Journal Article | ||
Year | 2007 | Publication | IEEE Trans. Appl. Supercond. | Abbreviated Journal | IEEE Trans. Appl. Supercond. |
Volume | 17 | Issue | 2 | Pages | 399-402 |
Keywords | NbN HEB mixers | ||||
Abstract | We report that the heterodyne sensitivity of superconducting hot-electron bolometers (HEBs) increases by 25-30% after annealing at 85degC in high vacuum. The devices studied are twin-slot antenna coupled mixers with a small area NbN bridge of 1 mum times 0.15 mum, above which there is a SiO 2 passivation layer. The mixer noise temperature, gain, and resistance versus temperature curve of a HEB before and after annealing are compared and analysed. We show that the annealing reduces the intrinsic noise of the mixer by 37% and makes the superconducting transition of the bridge and the contacts sharper. We argue that the reduction ofthe noise is mainly due to the improvement of the transparency of the contact/film interface. The lowest receiver noise temperature of 700 K is measured at a local oscillator frequency of 1.63 THz and at a bath temperature of 4.2 K. | ||||
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ISSN | 1051-8223 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | Serial | 1426 | |||
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