|   | 
Details
   web
Records
Author Ryabchun, Sergey; Tong, Cheuk-Yu Edward; Paine, Scott; Lobanov, Yury; Blundell, Raymond; Goltsman, Gregory
Title Temperature resolution of an HEB receiver at 810 GHz Type (up) Journal Article
Year 2009 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 19 Issue 3 Pages 293-296
Keywords HEB mixer
Abstract We present the results of direct measurements of the temperature resolution of an HEB receiver operating at 810 GHz, in both continuum and spectroscopic modes. In the continuum mode, the input of the receiver was switched between black bodies with different physical temperatures. With a system noise temperature of around 1100 K, the receiver was able to resolve loads which differed in temperature by about 1 K over an integration time of 5 seconds. This resolution is significantly worse than the value of 0.07 K given by the radiometer equation. In the spectroscopic mode, a gas cell filled with carbonyl sulphide (OCS) gas was used and the emission line at 813.3537060 GHz was measured using the receiver in conjunction with a digital spectrometer. From the observed spectra, we determined that the measurement uncertainty of the equivalent emission temperature was 2.8 K for an integration time of 0.25 seconds and a spectral resolution of 12 MHz, compared to a 1.4 K temperature resolution given by the radiometer equation. This relative improvement is due to the fact that at short integration times the contribution from 1/f noise and drift are less dominant. In both modes, the temperature resolution was improved by about 40% with the use of a feedback loop which adjusted the level of an injected microwave radiation to maintain a constant operating current of the HEB mixer. This stabilization scheme has proved to be very effective to keep the temperature resolution of the HEB receiver to close to the theoretical value given by the radiometer equation.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 636
Permanent link to this record
 

 
Author Karpowicz, Nicholas; Lu, Xiaofei; Zhang, X.-C.
Title Terahertz gas photonics Type (up) Journal Article
Year 2009 Publication J. Modern Opt. Abbreviated Journal
Volume 56 Issue 10 Pages 1137-1150
Keywords
Abstract The underlying physics of the generation and detection of terahertz (THz) waves in gases are described. The THz wave generation process takes place in two steps: asymmetric gas ionization by two-frequency laser fields, followed by interaction of the ionized electron wave packets with the surrounding medium, producing an intense ‘echo' with tunable spectral content. In order to clarify the physical picture at the moment of ionization, the laser–atom interaction is treated through solution of the time-dependent Schrödinger equation, yielding an ab initio understanding of the release of the electron wave packets. The second step, where the electrons interact with the surrounding plasma is treated analytically. The resulting pressure dependence of the THz radiation is explored in detail. The THz wave detection process is shown to be the result of four-wave mixing, leading to analytical expressions of the signal obtained which allow for improved optimization of systems that exploit these effects.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number RPLAB @ gujma @ Serial 670
Permanent link to this record
 

 
Author Engel, Andreas; Aeschbacher, Adrian; Inderbitzin, Kevin; Schilling, Andreas; Il'in, Konstantin; Hofherr, Matthias; Siegel, Michael; Semenov, Alexei; Hübers, Heinz-Wilhelm
Title Tantalum nitride superconducting single-photon detectors with low cut-off energy Type (up) Journal Article
Year 2011 Publication arXiv Abbreviated Journal arXiv
Volume Issue Pages 9
Keywords SSPD
Abstract Materials with a small superconducting energy gap favor a high detection efficiency of low-energy photons in superconducting nanowire single-photon detectors. We developed a TaN detector with smaller gap and lower density of states at the Fermi energy than in comparable NbN devices, while other relevant parameters remain essentially unchanged. This results in a reduction of the minimum photon energy required for direct detection to $\approx1/3$ as compared to NbN.
Address
Corporate Author Thesis
Publisher Place of Publication arXiv:1110.4576 Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number RPLAB @ gujma @ Serial 687
Permanent link to this record
 

 
Author Jang, Young Rae; Yoo, Keon-Ho; Park, Seung Min
Title Rapid thermal annealing of ZnO thin films grown at room temperature Type (up) Journal Article
Year 2010 Publication J. Vac. Sci. Technol. A Abbreviated Journal
Volume 28 Issue 2 Pages 4
Keywords Annealing
Abstract The authors successfully obtained high quality ZnO thin films by growing them at room temperature (RT) and postannealing by rapid thermal annealing (RTA). The thin films were grown by pulsed laser deposition on Si (100) substrates at RT, and RTA was performed under various temperatures and ambient conditions. Based on the UV emission to visible emission ratio in RT photoluminescence (PL) spectra, the optimum film was obtained at annealing temperature ~700 °C in an ambient of Ar, N2, or O2 at 0.1 Torr, while the optimum annealing temperature was above 1100 °C in the air ambient at atmospheric pressure. The morphology and structure of the films in different RTA conditions were investigated by using field emission scanning electron microscopy and grazing incidence x-ray diffraction, and were discussed in conjunction with the PL data.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Annealing Approved no
Call Number RPLAB @ gujma @ Serial 692
Permanent link to this record
 

 
Author Poglitsch, A.; Waelkens, C.; Geis, N.; Feuchtgruber, H.; Vandenbussche, B.; Rodriguez, L.; Krause, O.; Renotte, E.; van Hoof, C.; Saraceno, P.; Cepa, J.; Kerschbaum, F.; Agnèse, P.; Ali, B.; Altieri, B.; Andreani, P.; Augueres, J.-L.; Balog, Z.; Barl, L.; Bauer, O. H.; Belbachir, N.; Benedettini, M.; Billot, N.; Boulade, O.; Bischof, H.; Blommaert, J.; Callut, E.; Cara, C.; Cerulli, R.; Cesarsky, D.; Contursi, A.; Creten, Y.; De Meester, W.; Doublier, V.; Doumayrou, E.; Duband, L.; Exter, K.; Genzel, R.; Gillis, J.-M.; Grözinger, U.; Henning, T.; Herreros, J.; Huygen, R.; Inguscio, M.; Jakob, G.; Jamar, C.; Jean, C.; de Jong, J.; Katterloher, R.; Kiss, C.; Klaas, U.; Lemke, D.; Lutz, D.; Madden, S.; Marquet, B.; Martignac, J.; Mazy, A.; Merken, P.; Montfort, F.; Morbidelli, L.; Müller, T.; Nielbock, M.; Okumura, K.; Orfei, R.; Ottensamer, R.; Pezzuto, S.; Popesso, P.; Putzeys, J.; Regibo, S.; Reveret, V.; Royer, P.; Sauvage, M.; Schreiber, J.; Stegmaier, J.; Schmitt, D.; Schubert, J.; Sturm, E.; Thiel, M.; Tofani, G.; Vavrek, R.; Wetzstein, M.; Wieprecht, E.; Wiezorrek, E.
Title The Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory Type (up) Journal Article
Year 2010 Publication Astron. Astrophys. Abbreviated Journal A&A
Volume 518 Issue Pages 12
Keywords PACS
Abstract The Photodetector Array Camera and Spectrometer (PACS) is one of the three science instruments on ESA's far infrared and submillimetre observatory. It employs two Ge:Ga photoconductor arrays (stressed and unstressed) with 16×25 pixels, each, and two filled silicon bolometer arrays with 16×32 and 32×64 pixels, respectively, to perform integral-field spectroscopy and imaging photometry in the 60-210 μm wavelength regime. In photometry mode, it simultaneously images two bands, 60-85 μm or 85-125 μm and 125-210 μm, over a field of view of ~1.75'× 3.5', with close to Nyquist beam sampling in each band. In spectroscopy mode, it images a field of 47” × 47”, resolved into 5×5 pixels, with an instantaneous spectral coverage of ~1500 km s-1 and a spectral resolution of ~175 km s-1. We summarise the design of the instrument, describe observing modes, calibration, and data analysis methods, and present our current assessment of the in-orbit performance of the instrument based on the performance verification tests. PACS is fully operational, and the achieved performance is close to or better than the pre-launch predictions.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number RPLAB @ gujma @ Serial 694
Permanent link to this record