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| Author | Kawamura, J.; Hunter, T. R.; Tong, C. Y. E.; Blundell, R.; Papa, D. C.; Patt, F.; Peters, W.; Wilson, T.; Henkel, C.; Goltsman, G.; Gershenzon, E. | ||||
| Title | Ground-based terahertz CO spectroscopy towards Orion | Type | Journal Article | ||
| Year | 2002 | Publication | A&A | Abbreviated Journal  |
A&A |
| Volume | 394 | Issue | 1 | Pages | 271-274 |
| Keywords | HEB mixers, applications | ||||
| Abstract | Using a superconductive hot-electron bolometer heterodyne receiver on the 10-m Heinrich Hertz Telescope on Mount Graham, Arizona, we have obtained velocity-resolved 1.037 THz CO () spectra toward several positions along the Orion Molecular Cloud (OMC-1) ridge. We confirm the general results of prior observations of high-J CO lines that show that the high temperature, , high density molecular gas, , is quite extended, found along a ~ region centered on BN/KL. However, our observations have significantly improved angular resolution, and with a beam size of we are able to spatially and kinematically discriminate the emission originating in the extended quiescent ridge from the very strong and broadened emission originating in the compact molecular outflow. The ridge emission very close to the BN/KL region appears to originate from two distinct clouds along the line of sight with and ≈ . The former component dominates the emission to the south of BN/KL and the latter to the north, with a turnover point coincident with or near BN/KL. Our evidence precludes a simple rotation of the inner ridge and lends support to a model in which there are multiple molecular clouds along the line of sight towards the Orion ridge. | ||||
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| Notes | Approved | no | |||
| Call Number | Serial | 322 | |||
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| Author | Ren, Y.; Zhang, D. X.; Zhou, K. M.; Miao, W.; Zhang, W.; Shi, S. C.; Seleznev, V.; Pentin, I.; Vakhtomin, Y.; Smirnov, K. | ||||
| Title | 10.6 μm heterodyne receiver based on a superconducting hot-electron bolometer mixer and a quantum cascade laser | Type | Journal Article | ||
| Year | 2019 | Publication | AIP Advances | Abbreviated Journal |
AIP Advances |
| Volume | 9 | Issue | 7 | Pages | 075307 |
| Keywords | NbN HEB mixers, QCL, IR | ||||
| Abstract | We report on the development of a heterodyne receiver at mid-infrared wavelength for high-resolution spectroscopy applications. The receiver employs a superconducting NbN hot electron bolometer as a mixer and a room temperature distributed feedback quantum cascade laser operating at 10.6 μm (28.2 THz) as a local oscillator. The stabilization of the heterodyne receiver has been achieved using a feedback loop controlling the output power of the laser. Improved Allan variance times as well as a double sideband receiver noise temperature of 5000 K and a noise bandwidth of 2.8 GHz of the receiver system are demonstrated. The work is supported in part by the National Key R&D Program of China under Grant 2018YFA0404701, by the CAS program under Grant QYZDJ-SSW-SLH043 and GJJSTD20180003, by the National Natural Science Foundation of China (NSFC) under Grant 11773083, by the “Hundred Talents Program” of the “Pioneer Initiative”, and in part by the CAS Key Lab for Radio Astronomy. |
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| ISSN | 2158-3226 | ISBN | Medium | ||
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| Notes | Approved | no | |||
| Call Number | Serial | 1293 | |||
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| Author | Ekstörm, H.; Kollberg, E.; Yagoubov, P.; Gol'tsman, G.; Gershenzon, E.; Yngvesson, S. | ||||
| Title | Gain and noise bandwidth of NbN hot-electron bolometric mixers | Type | Journal Article | ||
| Year | 1997 | Publication | Appl. Phys. Lett. | Abbreviated Journal |
Appl. Phys. Lett. |
| Volume | 70 | Issue | 24 | Pages | 3296-3298 |
| Keywords | NbN HEB mixers, conversion loss, conversion gain, U-factor technique | ||||
| Abstract | We have measured the noise performance and gain bandwidth of 35 Å thin NbN hot-electron mixers integrated with spiral antennas on silicon substrate lenses at 620 GHz. The best double-sideband receiver noise temperature is less than 1300 K with a 3 dB bandwidth of ≈5 GHz. The gain bandwidth is 3.2 GHz. The mixer output noise dominated by thermal fluctuations is 50 K, and the intrinsic conversion gain is about −12 dB. Without mismatch losses and excluding the loss from the beamsplitter, we expect to achieve a receiver noise temperature of less than 700 K. | ||||
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| Notes | Approved | no | |||
| Call Number | Serial | 279 | |||
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| Author | Khosropanah, P.; Gao, J. R.; Laauwen, W. M.; Hajenius, M; Klapwijk, T. M. | ||||
| Title | Low noise NbN hot electron bolometer mixer at 4.3 THz | Type | Journal Article | ||
| Year | 2007 | Publication | Appl. Phys. Lett. | Abbreviated Journal |
Appl. Phys. Lett. |
| Volume | 91 | Issue | Pages | 221111 (1 to 3) | |
| Keywords | NbN HEB mixers, NbN, contacts cleaning | ||||
| Abstract | We have studied the sensitivity of a superconducting NbN hot electron bolometer mixer integrated with a spiral antenna at 4.3 THz. Using hot/cold blackbody loads and a beam splitter all in vacuum, we measured a double sideband receiver noise temperature of 1300 K at the optimum local oscillator (LO) power of 330 nW, which is about 12 times the quantum noise (hnu/2kB). Our result indicates that there is no sign of degradation of the mixing process at the superterahertz frequencies. Moreover, a measurement method is introduced which allows us for an accurate determination of the sensitivity despite LO power fluctuations. | ||||
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| Notes | Approved | no | |||
| Call Number | Serial | 584 | |||
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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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