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| Author |
Meledin, D. V.; Marrone, D. P.; Tong, C.-Y. E.; Gibson, H.; Blundell, R.; Paine, S. N.; Papa, D.C.; Smith, M.; Hunter, T. R.; Battat, J.; Voronov, B.; Gol'tsman, G. |
Title  |
A 1-THz superconducting hot-electron-bolometer receiver for astronomical observations |
Type |
Journal Article |
| Year |
2004 |
Publication |
IEEE Trans. Microwave Theory Techn. |
Abbreviated Journal |
IEEE Trans. Microwave Theory Techn. |
| Volume |
52 |
Issue |
10 |
Pages |
2338-2343 |
| Keywords |
NbN HEB mixer, applications |
| Abstract |
In this paper, we describe a superconducting hot-electron-bolometer mixer receiver developed to operate in atmospheric windows between 800-1300 GHz. The receiver uses a waveguide mixer element made of 3-4-nm-thick NbN film deposited over crystalline quartz. This mixer yields double-sideband receiver noise temperatures of 1000 K at around 1.0 THz, and 1600 K at 1.26 THz, at an IF of 3.0 GHz. The receiver was successfully tested in the laboratory using a gas cell as a spectral line test source. It is now in use on the Smithsonian Astrophysical Observatory terahertz test telescope in northern Chile. |
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0018-9480 |
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1484 |
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Pan, S. K.; A. R. Kerr, M. W. Pospieszalski; Lauria, E. F.; Crady, W. K.; Horner, N.; Srikanth, Jr. S.; Bryerton, E.; Saini, K.; Claude, S. M. X.; Chin, C. C.; Dindo, P.; Rodrigues, G.; Derdall, D.; Zhang, J. Z.; Lichtenberger, A. W. |
| Title |
A fixed-tuned integrated SIS mixer with ultra-wideband IF and quantum-limited sensitivity for ALMA band 3 (84-116 GHz) receivers |
Type |
Conference Article |
| Year |
2004 |
Publication |
Proc. 15th Int. Symp. Space Terahertz Technol. |
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55-61 |
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Northampton, MA |
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RPLAB @ s @ SIS_bandw_8GHz |
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358 |
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Slysz, W.; Wegrzecki, M.; Papis, E.; Gol'tsman, G. N.; Verevkin, A.; Sobolewski, R. |
| Title |
A method of optimization of the NbN superconducting single-photon detector |
Type |
Miscellaneous |
| Year |
2004 |
Publication |
INIS |
Abbreviated Journal |
INIS |
| Volume |
36 |
Issue |
27 |
Pages |
1-2 |
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NbN SSPD, SNSPD |
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5-th International Symposium Ion Implantation and Other Applications of Ions and Electrons, ION |
| Notes |
Reference num. 36060124 |
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1485 |
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Genack, Azriel Z.; Kopp, Victor I.; Churikov, Victor M.; Singer, Jonathan; Chao, Norman; Neugroschl, Daniel A. |
| Title |
Chiral fiber Bragg gratings |
Type |
Conference Article |
| Year |
2004 |
Publication |
Proceedings of the SPIE |
Abbreviated Journal |
Proc. SPIE |
| Volume |
5508 |
Issue |
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Pages |
57-64 |
| Keywords |
optical fiber gratings, chiral fiber gratings, chiral gratings, from chiralphotonics |
| Abstract |
We have produced chiral fiber Bragg gratings with double-helix symmetry and measured the polarization and wavelength selective transmission properties of these structures. These gratings interact only with circularly polarized light with the same handedness as the grating twist and freely transmit light of the orthogonal polarization. The optical characteristics of chiral fibers are compared to those of planar cholesteric structures. The resonant standing wave at the band edge or at a defect state within the band gap, as well as the evanescent wave within the band gap is comprised of two counterpropagating components of equal amplitude. The electric field vector of such a circularly polarized standing wave does not rotate in time; rather it is linearly polarized in any given plane. The standing wave may be described in terms of the sense of circular polarization of the two counterpropagating components. The wavelength dependence of the angle q between the linearly polarized electromagnetic field and the extraordinary axis, which is constant throughout a long structure, is obtained in a simple calculation. The results are in good agreement with scattering matrix calculations. Resonant chiral gratings are demonstrated for microwave radiation whereas chiral gratings with pitch exceeding the wavelength are demonstrated at optical wavelengths in single-mode glass fibers. The different functionalities of these fibers are discussed. |
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854 |
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Meledin D.; Pantaleev M.; Pavolotsky A.; Risacher C.; Robles V.A.P.; Belitsky V.; Drakinskiy V.; Cherednichenko S. |
| Title |
Design of a balanced waveguide HEB mixer for APEX 1.32 THz receiver |
Type |
Conference Article |
| Year |
2004 |
Publication |
Proc. 15th Int. Symp. Space Terahertz Technol. |
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Pages |
211-217 |
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The prototype of a waveguide balanced Hot Electron Bolometer (HEB) Terahertz mixer is designed as a part of development for the APEX Project of Band T2 receiver for 1250-1390 GHz. The proposed mixer employs balanced scheme with two identical HEB devices. These individual mixers would be placed on two separate crystalline quartz substrates with dimensions of 1000μm x67μm x17 μm each with integrated RF choke filters, DC-bias and IF circuitry. A 3 dB quadrature waveguide directional coupler is needed to provide local oscillator (LO) injection and RF signal distribution between the two HEB mixers. We have designed the coupler to achieve the required frequency band, low insertion loss and symmetrical division of the RF and LO power within the band of interest. Initial design of HEB mixer layout is developed based on a previous development for a 345 GHz sideband separation mixer. We present also results of development of microfabrication technology of the waveguide hybrid employing micromachining approach combined with electroplating technique. |
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RPLAB @ atomics90 @ |
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972 |
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Krasnopolsky, Vladimir A.; Maillard, Jean Pierre; C. Owen, Tobias |
| Title |
Detection of methane in the martian atmosphere: evidence for life? |
Type |
Journal Article |
| Year |
2004 |
Publication |
Icarus |
Abbreviated Journal |
Icarus |
| Volume |
172 |
Issue |
2 |
Pages |
537-547 |
| Keywords |
FTS, Mars atmosphere, methane absorption lines, IR spectroscopy, infrared spectroscopy, landfill gas |
| Abstract |
Using the Fourier Transform Spectrometer at the Canada–France–Hawaii Telescope, we observed a spectrum of Mars at the P-branch of the strongest CH4 band at 3.3 μm with resolving power of 180,000 for the apodized spectrum. Summing up the spectral intervals at the expected positions of the 15 strongest Doppler-shifted martian lines, we detected the absorption by martian methane at a 3.7 sigma level which is exactly centered in the summed spectrum. The observed CH4 mixing ratio is 10±3 ppb. Total photochemical loss of CH4 in the martian atmosphere is equal to View the MathML source, the CH4 lifetime is 340 years and methane should be uniformly mixed in the atmosphere. Heterogeneous loss of atmospheric methane is probably negligible, while the sink of CH4 during its diffusion through the regolith may be significant. There are no processes of CH4 formation in the atmosphere, so the photochemical loss must therefore be balanced by abiogenic and biogenic sources. Outgassing from Mars is weak, the latest volcanism is at least 10 million years old, and thermal emission imaging from the Mars Odyssey orbiter does not reveal any hot spots on Mars. Hydrothermal systems can hardly be warmer than the room temperature at which production of methane is very low in terrestrial waters. Therefore a significant production of hydrothermal and magmatic methane is not very likely on Mars. The calculated average production of CH4 by cometary impacts is 2% of the methane loss. Production of methane by meteorites and interplanetary dust does not exceed 4% of the methane loss. Methane cannot originate from an extinct biosphere, as in the case of “natural gas†on Earth, given the exceedingly low limits on organic matter set by the Viking landers and the dry recent history which has been extremely hostile to the macroscopic life needed to generate the gas. Therefore, methanogenesis by living subterranean organisms is a plausible explanation for this discovery. Our estimates of the biomass and its production using the measured CH4 abundance show that the martian biota may be extremely scarce and Mars may be generally sterile except for some oases. |
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Serial |
879 |
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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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no |
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352 |
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Baselmans, J. J. A.; Hajenius, M.; Gao, J.; de Korte, P.; Klapwijk, T. M.; Voronov, B.; Gol’tsman, G. |
| Title |
Doubling of sensitivity and bandwidth in phonon-cooled hot-electron bolometer mixers |
Type |
Conference Article |
| Year |
2004 |
Publication |
Proc. SPIE |
Abbreviated Journal |
Proc. SPIE |
| Volume |
5498 |
Issue |
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Pages |
168-176 |
| Keywords |
Hot electron bolometers, bandwidth, noise temperature, experimental |
| Abstract |
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 the NbN bolometer and the contact pad. We compare identical bolometers, with different NbN – contact pad interfaces, coupled with a spiral antenna. We find that cleaning the NbN interface and adding a thin additional superconductor prior to the gold contact deposition improves the noise temperature and the bandwidth of the HEB mixers with more than a factor of 2. We obtain a DSB noise temperature of 950 K at 2.5 THz and a Gain bandwidth of 5-6 GHz. For use in real receiver systems we design small volume (0.15x1 micron) HEB mixers with a twin slot antenna. We find that these mixers combine good sensitivity (900 K at 1.6 THz) with low LO power requirement, which is 160 – 240 nW at the Si lens of the mixer. This value is larger than expected from the isothermal technique and the known losses in the lens by a factor of 3-3.5. |
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SPIE |
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Zmuidzinas, J.; Holland, W.S.; Withington, S. |
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Millimeter and Submillimeter Detectors for Astronomy II |
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no |
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1744 |
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Hubers, H.-W.; Semenov, A.; Richter, H.; Schwarz, M.; Gunther, B.; Smirnov, K.; Gol’tsman, G.; Voronov, B. |
| Title |
Heterodyne receiver for 3-5 THz with hot-electron bolometer mixer |
Type |
Conference Article |
| Year |
2004 |
Publication |
Proc. SPIE |
Abbreviated Journal |
Proc. SPIE |
| Volume |
5498 |
Issue |
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Pages |
579-586 |
| Keywords |
NbN HEB mixers |
| Abstract |
Heterodyne receivers for applications in astronomy and planetary research need quantum limited sensitivity. In instruments which are currently build for SOFIA and Herschel superconducting hot electron bolometers (HEB) will be used to achieve this goal at frequencies above 1.4 THz. The local oscillator and the mixer are the most critical components for a heterodyne receiver operating at 3-5 THz. The design and performance of an optically pumped THz gas laser optimized for this frequency band will be presented. In order to optimize the performance for this frequency hot electron bolometer mixers with different in-plane dimensions and logarithmic-spiral feed antennas have been investigated. Their noise temperatures and beam patterns were measured. Above 3 THz the best performance was achieved with a superconducting bridge of 2.0 x 0.2 μm2 incorporated in a logarithmic spiral antenna. The DSB noise temperatures were 2700 K, 4700 K and 6400 K at 3.1 THz, 4.3 THz and 5.2 THz, respectively. The results demonstrate that the NbN HEB is very well suited as a mixer for THz heterodyne receivers up to at least 5 THz. |
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SPIE |
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Zmuidzinas, J.; Holland, W.S.; Withington, S. |
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Millimeter and Submillimeter Detectors for Astronomy II |
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no |
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1483 |
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Baselmans, J. J. A.; Hajenius, M.; Gao, J. R.; Baryshev, A.; Kooi, J.; Klapwijk, T. M.; de Korte, P. A. J.; Voronov, B.; Gol’tsman, G. |
| Title |
Hot electron bolometer mixers with improved interfaces: sensitivity, LO power and stability |
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Conference Article |
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2004 |
Publication |
Proc. 15th Int. Symp. Space Terahertz Technol. |
Abbreviated Journal |
Proc. 15th Int. Symp. Space Terahertz Technol. |
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17-24 |
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NbN HEB mixers |
| Abstract |
We study twin slot antenna coupled NbN hot electron bolometer mixers with an improved contact structure and a small volume, ranging from 1 µm × 0.1 µm to 2 × 0.3 µm. We obtain a DSB receiver noise temperature of 900 K at 1.6 THz and 940 K at 1.9 THz. To explore the practical usability of such small HEB mixers we evaluate the LO power requirement, the sensitivity and the stability. We find that the LO power requirement of the smallest mixers is reduced to about 240 nW at the Si lens of the mixer. This value is larger than expected from the isothermal technique and the known losses in the lens by a factor of 3-3.5. The stability of these receivers is characterized using a measurement of the Allan Variance. We find an Allan time of 0.5 sec. in an 80 MHz bandwidth. A small increase in stability can be reached by using a higher bias at the expense of a significant amount of sensitivity. The stability is sufficient for spectroscopic applications in a 1 MHz bandwidth at a 1 Hz chopping frequency. |
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1491 |
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Ozhegov, R.; Maslennikov, S.; Morozov, D.; Okunev, O.; Smirnov, K.; Gol'tsman, G. |
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Imaging system for submillimeter wave range |
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Conference Article |
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2004 |
Publication |
Proc. Tenth All-Russian sceintific conference of student-physicists and young sceintists (VNKSF-10) |
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Moscow |
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RPLAB @ s @ thzimaging_vnksf10_2004 |
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347 |
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Maslennikov, S. N.; Morozov, D. V.; Ozhegov, R. V.; Smirnov, K. V.; Okunev, O. V.; Gol’tsman, G. N. |
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Imaging system for submillimeter wave range based on AlGaAs/GaAs hot electron bolometer mixers |
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Conference Article |
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2004 |
Publication |
Proc. 5-th MSMW |
Abbreviated Journal |
Proc. 5-th MSMW |
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2 |
Issue |
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Pages |
558-560 |
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AlGaAs/GaAs HEB mixers |
| Abstract |
Electromagnetic radiation of the submillimeter (SMM) range is dispersed and absorbed significantly less than infrared (IR) radiation when passing through different objects. That is the reason for the development of an SMM imaging system. In this paper, we discuss the design of an SMM heterodyne imager, based on a matrix of AlGaAs/GaAs heterostructure hot electron bolometer mixers (HEB) with relatively high (about 77 K) operating temperature. The predicted double side band (DSB) noise temperature is about 1000 K and optimal local oscillator (LO) power is about 1 /spl mu/W for such mixers, which seems to be quite prospective for an SMM heterodyne imager. |
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Kharkov, Ukraine |
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The Fifth International Kharkov Symposium on Physics and Engineering of Microwaves, Millimeter, and Submillimeter Waves (IEEE Cat. No.04EX828) |
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1487 |
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Klapwijk, T. M.; Barends, R.; Gao, J. R.; Hajenius, M.; Baselmans, J. J. A. |
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Improved superconducting hot-electron bolometer devices for the THz range |
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Conference Article |
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2004 |
Publication |
Proc. SPIE |
Abbreviated Journal |
Proc. SPIE |
| Volume |
5498 |
Issue |
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Pages |
129-139 |
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HEB mixer distributed model, numerical model |
| Abstract |
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 conditions during the mixing process. We find that the mixing is predominantly due to the exponential rise of the local resistivity as a function of electron temperature. |
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Invited talk, Recommended by Klapwijk |
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no |
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912 |
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Hajenius, M.; Baselmans, J. J. A.; Gao, J. R.; Klapwijk, T. M.; de Korte 2, P. A. J.; Voronov, B.; Gol’tsman, G. |
| Title |
Increased bandwidth of NbN phonon cooled hot electron bolometer mixers |
Type |
Conference Article |
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2004 |
Publication |
Proc. 15th Int. Symp. Space Terahertz Technol. |
Abbreviated Journal |
Proc. 15th Int. Symp. Space Terahertz Technol. |
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381-386 |
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NbN HEB mixers, IF bandwidth |
| Abstract |
We study experimentally the IF gain bandwidth of NbN phonon-cooled hot-electron-bolometer (HEB) mixers for a set of devices with different contact structures but an identical NbN film. We observe that the IF bandwidth depends strongly on the exact contact structure and find an IF gain bandwidth of 6 GHz for a device with an additional superconducting layer (NbTiN) in between the active NbN film and the gold contact to the antenna. These results contradict the common opinion that the IF bandwidth is determined by the phonon-escape time between the NbN film and the substrate. Hence we calculate the IF gain bandwidth of a superconducting film using a two-temperature model. We find that the bandwidth increases strongly with operating temperature and is not limited by the phonon escape time. This is because of strong temperature dependence of the phonon specific heat in the NbN film. |
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| Author |
González, Francisco Javier; Alda, Javier; Ilic, Bojan; Boreman, Glenn D. |
| Title |
Infrared Antennas Coupled to Lithographic Fresnel Zone Plate Lenses |
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Journal Article |
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2004 |
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Applied Optics |
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Appl. Opt. |
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43 |
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33 |
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6067-6073 |
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optical antennas |
| Abstract |
Several designs for Fresnel zone plate lenses (FZPLs) to be used in conjunction with antenna-coupled infrared detectors have been fabricated and tested. The designs comprise square and circular FZPLs with different numbers of Fresnel zones working in transmissive or reflective modes designed to focus infrared energy on a square-spiral antenna connected to a microbolometer. A 163× maximum increase in response was obtained from a 15-zone circular FZPL in the transmissive mode. Sensor measurements of normalized detectivity D* resulted in a 2.67× increase with FZPLs compared with measurements made of square-spiral antennas without FZPLs. The experimental results are discussed and compared with values obtained from theoretical calculations. |
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RPLAB @ gujma @ |
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