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Author Shurakov, Alexander; Tong, Cheuk-yu E.; Blundell, Raymond; Gol’tsman, Gregory
Title A microwave pumped HEB direct detector using a homodyne readout scheme Type Abstract
Year 2014 Publication Proc. 25th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 25th Int. Symp. Space Terahertz Technol.
Volume Issue Pages (up) 129
Keywords waveguide NbN HEB detector, NEP
Abstract We report the results of our study on the noise performance of a fast THz detector based on the repurpose of hot electron bolometer mixer (HEB). Instead of operating with an elevated bath temperature, microwave power is injected into the HEB device, which enhances the sensitivity of the detector and at the same time provide a mechanism for reading out impedance changes of the device induced by the modulated incident THz radiation [1]. We have demonstrated an improvement of the detector’s optical noise equivalent power (NEP). Furthermore, by introducing a homodyne readout scheme based on a room temperature microwave mixer, the dynamic range of the detector is increased. The HEB devices used in this work were made of 4 nm thick NbN film. The detector chips were installed into a waveguide mixer block fitted with a corrugated horn, mounted on the cold plate of a liquid helium cryostat. The HEBs were operated at a bath temperature of 4.2 K. The signal beam was terminated on black bodies at ambient and liquid nitrogen temperatures. A chopper wheel placed in front of the cryostat window operating at a frequency of 1.48 kHz modulated the input load temperature of the detector. A cold mesh filter, centered at 830 GHz, was used to define the input signal power bandwidth. Microwave was injected through a broadband directional coupler inside the cryostat. Our experiments were mostly conducted at a pump frequency of 1.5 GHz. The reflected microwave power from the HEB device was fed into a cryogenic low noise amplifier (LNA). The output of the LNA was connected to the RF input port of a room temperature microwave mixer, which beat the reflected signal from the HEB using a copy of the original 1.5 GHz injection signal in a homodyne demodulation scheme. The amplitude of the detected power was measured by a lock-in amplifier, which was synchronized to the chopper frequency. Preliminary results yield an optical NEP of ~1 pW/ Hz 1/2 which corresponds to an improvement of a factor of 3 compared to [1], driven mainly by a lowering of the system noise floor. The dynamic range was also increased by similar amount. References 1. A. Shurakov et al. “A Microwave Pumped Hot Electron Bolometric Direct Detector,” submitted on Oct 18, 2013 to Appl. Phys. Let.
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Call Number Serial 1365
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Author Hansen, Lene; Jørgensen, H.E.; Nørgaard-Nielsen, Hans Ulrik; Pedersen, Kenneth; Goudfrooij, P.; Linden-Vornle, M.J.D.
Title ISO far-infrared observations of rich galaxy clusters III. Abell 2029, Abell 2052, Abell 2142 Type Journal Article
Year 2000 Publication Astron. Astrophys. Abbreviated Journal A&A
Volume 362 Issue 1 Pages (up) 133-137
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Abstract A sample of five rich galaxy clusters has been mapped by ISO at 60 μm, 100 μm, 135 μm, and 200 μm using the PHT-C camera. In previous papers Abell 2670 and Sersic 159-03 were discussed. Here we present the results for Abell 2029, Abell 2052, and Abell 2142. The conclusion of the survey is that the relatively small fields (approximate to 60 square are minutes) are structured with filaments or superpositions of point sources. In some cases point sources (approximate to 0.1 Jy) can be identified with cluster galaxies. An attempt to demonstrate infrared emission from dust in the cooling flows (due to star formation) was inconclusive.
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Call Number RPLAB @ s @ Serial 456
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Author Yagoubov, P.; Kroug, M.; Merkel, H.; Kollberg, E.; Schubert, J.; Hubers, H.-W.; Schwaab, G.; Gol’tsman, G.; Gershenzon, E.
Title Performance of NbN phonon-cooled hot-electron bolometric mixer at Terahertz frequencies Type Conference Article
Year 1998 Publication Proc. 6-th Int. Conf. Terahertz Electron. Abbreviated Journal Proc. 6-th Int. Conf. Terahertz Electron.
Volume Issue Pages (up) 149-152
Keywords NbN HEB mixers
Abstract The performance of a NbN based phonon-cooled Hot Electron Bolometric (HEB) quasioptical mixer is investigated in the 0.65-3.12 THz frequency range. The device is made from a 3 nm thick NbN film on high resistivity Si and integrated with a planar spiral antenna on the same substrate. The in-plane dimensions of the bolometer strip are 0.2/spl times/2 /spl mu/m. The results of the DSB noire temperature are: 1300 K at 650 GHz, 4700 K at 2.5 TBz and 10000 K at 3.12 THz. The RF bandwidth of the receiver is at least 2.5 THz. The amount of LO power absorbed in the bolometer is about 100 nW. The mixer is linear to within 1 dB compression up to the signal level 10 dB below that of the LO. The intrinsic single sideband conversion gain is measured to be -9 dB, the total conversion gain -14 dB.
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Area Expedition Conference IEEE Sixth International Conference on Terahertz Electronics Proceedings. THZ 98. (Cat. No.98EX171)
Notes Approved no
Call Number Serial 1582
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Author Hartogh, P.; Crovisier, J.; de Val-Borro, M.; Bockelée-Morvan, D.; Biver, N.; Lis, D. C.; Moreno, R.; Jarchow, C.; Rengel, M.; Emprechtinger, M.; Szutowicz, S.; Banaszkiewicz, M.; Bensch, F.; Blecka, M. I.; Cavalié, T.; Encrenaz, T.; Jehin, E.; Küppers, M.; Lara, L.-M.; Lellouch, E.; Swinyard, B. M.; Vandenbussche, B.; Bergin, E. A.; Blake, G. A.; Blommaert, J. A. D. L.; Cernicharo, J.; Decin, L.; Encrenaz, P.; de Graauw, T.; Hutsemekers, D.; Kidger, M.; Manfroid, J.; Medvedev, A. S.; Naylor, D. A.; Schieder, R.; Thomas, N.; Waelkens, C.; Roelfsema, P. R.; Dieleman, P.; Güsten, R.; Klein, T.; Kasemann, C.; Caris, M.; Olberg, M.; Benz, A. O.
Title HIFI observations of water in the atmosphere of comet C/2008 Q3 (Garradd) Type Journal Article
Year 2010 Publication Astron. Astrophys. Abbreviated Journal
Volume 518 Issue Pages (up) L150 (1 to 5)
Keywords HEB mixer applications, HIFI, Herschel, comets: individual: C/2008 Q3 / radio lines: general / submillimeter: general / techniques: spectroscopic
Abstract High-resolution far-infrared and sub-millimetre spectroscopy of water lines is an important tool to understand the physical and chemical properties of cometary atmospheres. We present observations of several rotational ortho- and para-water transitions in comet C/2008 Q3 (Garradd) performed with HIFI on Herschel. These observations have provided the first detection of the 212–101 (1669 GHz) ortho and 111–000 (1113 GHz) para transitions of water in a cometary spectrum. In addition, the ground-state transition 110–101 at 557 GHz is detected and mapped. By detecting several water lines quasi-simultaneously and mapping their emission we can constrain the excitation parameters in the coma. Synthetic line profiles are computed using excitation models which include excitation by collisions, solar infrared radiation, and radiation trapping. We obtain the gas kinetic temperature, constrain the electron density profile, and estimate the coma expansion velocity by analyzing the map and line shapes. We derive water production rates of 1.7–2.8 × 1028 s-1 over the range rh = 1.83–1.85 AU.
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Call Number Serial 1088
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Author Palermo, C.; Varani, L.; Vaissière, J.-C.; Millithaler, J.-F.; Starikov, E.; Shiktorov, P.; Gruzinskis, V.; Azaïs, B.
Title Monte Carlo calculation of diffusion coefficient, noise spectral density and noise temperature in HgCdTe Type Conference Article
Year 2005 Publication Proc. AIP Conf. Abbreviated Journal
Volume 780 Issue Pages (up) 151-154
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Call Number Serial 460
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