|
|
Divochiy, A., Misiaszek, M., Vakhtomin, Y., Morozov, P., Smirnov, K., Zolotov, P., et al. (2018). Single photon detection system for visible and infrared spectrum range. Opt. Lett., 43(24), 6085–6088.
Abstract: We demonstrate niobium nitride based superconducting single-photon detectors sensitive in the spectral range 452-2300 nm. The system performance was tested in a real-life experiment with correlated photons generated by means of spontaneous parametric downconversion, where one photon was in the visible range and the other was in the infrared range. We measured a signal to noise ratio as high as 4x10(4) in our detection setting. A photon detection efficiency as high as 64% at 1550 nm and 15% at 2300 nm was observed.
|
|
|
|
Dryazgov, M., Semenov, A., Manova, N., Korneeva, Y., & Korneev, A. (2020). Modelling of normal domain evolution after single-photon absorption of a superconducting strip of micron width. In J. Phys.: Conf. Ser. (Vol. 1695, 012195 (1 to 4)).
Abstract: The present paper describes a modelling of normal domain evolution in superconducting strip of micron width using solving differential equations describing the temperature and current changes. The solving results are compared with experimental data. This comparison demonstrates the high accuracy of the model. In future, it is possible to employ this model for improvement of single photon detector based on micron-scale superconducting strips.
|
|
|
|
Dube, I., Jiménez, D., Fedorov, G., Boyd, A., Gayduchenko, I., Paranjape, M., et al. (2015). Understanding the electrical response and sensing mechanism of carbon-nanotube-based gas sensors. Carbon, 87, 330–337.
Abstract: Gas sensors based on carbon nanotube field effect transistors (CNFETs) have outstanding sensitivity compared to existing technologies. However, the lack of understanding of the sensing mechanism has greatly hindered progress on calibration standards and customization of these nano-sensors. Calibration requires identifying fundamental transistor parameters and establishing how they vary in the presence of a gas. This work focuses on modeling the electrical response of CNTFETs in the presence of oxidizing (NO2) and reducing (NH3) gases and determining how the transistor characteristics are affected by gas-induced changes of contact properties, such as the Schottky barrier height and width, and by the doping level of the nanotube. From the theoretical fits of the experimental transfer characteristics at different concentrations of NO2 and NH3, we find that the CNTFET response can be modeled by introducing changes in the Schottky barrier height. These changes are directly related to the changes in the metal work function of the electrodes that we determine experimentally, independently, with a Kelvin probe. Our analysis yields a direct correlation between the ON – current and the changes in the electrode metal work function. Doping due to molecules adsorbed at the carbon-nanotube/metal interface also affects the transfer characteristics.
|
|
|
|
Edward Tong, C. - Y., Loudkov, D. N., Paine, S. N., Marrone, D. P., & Blundell, R. (2005). Vector measurement of the beam pattern of a 1.5 THz superconducting HEB receiver. In Proc. 16th Int. Symp. Space Terahertz Technol. (pp. 453–456).
Abstract: Near-field vector beam pattern of the 1.5 THz superconducting Hot Electron Bolometer (HEB) receiver currently in operation in Northern Chile has been performed in our laboratory. Using an open waveguide probe, we have mapped both the amplitude and phase of the beam emerging from our 1.5 THz HEB receiver package, across a number of planes along the line of propagation of the radio-beam. With an integration time of about 100 ms per point, a signal-to-noise ratio of about 25 dB was achieved for a beam waist of 3.5 mm. These measurements have proved to be invaluable in achieving good alignment between the cryostat housing the HEB mixer and the remainder of the receiver and telescope optics. The accuracy of our beam measurement is estimated to be ±0.2 mm in position and ±5 arc minutes in angular displacement.
|
|
|
|
Ekström, H., Karasik, B., Kollberg, E., & Yngvesson, K. S. (1994). Investigation of a superconducting hot electron mixer. In Proc. 5th Int. Symp. Space Terahertz Technol. (pp. 169–188).
Abstract: Mixing at 20 GHz in niobium superconducting thin film strips in the resistive state is studied. Experiments give evidence that electron-heating is the main cause of the non linear phenomena. The requirements on the mode of operation and on the film parameters for small conversion loss and the possibility of conversion gain are discussed. Measurements indicate a minimum intrinsic conversion loss around 1 dB with a sharp drop for the lowest voltage bias-points, and a DSB mixer noise temperature between 100 and 450 K at 20 GHz. The device output noise temperature at the mixer operating point can be as low as 30-50 K. A simple theory is presented, which is based on the assumption that the small signal resistance is linearly dependent on power. This type of mixer is considered very promising for use in low-noise heterodyne receivers at THz frequencies.
|
|
|
|
Elant'ev, A. I., & Karasik, B. S. (1989). Effect of high-frequency current on Nb superconductive film in resistive state. Sov. J. Low Temp. Phys., 15(7), 379–383.
|
|
|
|
Elantev, A. I., & Karasik, B. S. (1994). Noise temperature of a superconducting hot-electron mixer. In Proc. 5th Int. Symp. Space Terahertz Technol. (225).
|
|
|
|
Eletskii, A. V., Sarychev, A. K., Boginskaya, I. A., Bocharov, G. S., Gaiduchenko, I. A., Egin, M. S., et al. (2018). Amplification of a Raman scattering signal by carbon nanotubes. Dokl. Phys., 63(12), 496–498.
Abstract: The effect of Raman scattering (RLS) signal amplification by carbon nanotubes (CNTs) was studied. Single-layered nanotubes were synthesized by the chemical vapor deposition (CVD) method using methane as a carbon-containing gas. The object of study used was water, the Raman spectrum of which is rather well known. Amplification of the Raman scattering signal by several hundred percent was attained in our work. The maximum amplification of a Raman scattering signal was shown to be achieved at an optimal density of nanotubes on a substrate. This effect was due to the scattering and screening of plasmons excited in CNTs by neighboring nanotubes. The amplification mechanism and the possibilities of optimization for this effect were discussed on the basis of the theory of plasmon resonance in carbon nanotubes.
|
|
|
|
Emelianov, A. V., Nekrasov, N. P., Moskotin, M. V., Fedorov, G. E., Otero, N., Romero, P. M., et al. (2021). Individual SWCNT transistor with photosensitive planar junction induced by two‐photon oxidation. Adv. Electron. Mater., 7(3), 2000872.
Abstract: The fabrication of planar junctions in carbon nanomaterials is a promising way to increase the optical sensitivity of optoelectronic nanometer-scale devices in photonic connections, sensors, and photovoltaics. Utilizing a unique lithography approach based on direct femtosecond laser processing, a fast and easy technique for modification of single-walled carbon nanotube (SWCNT) optoelectronic properties through localized two-photon oxidation is developed. It results in a novel approach of quasimetallic to semiconducting nanotube conversion so that metal/semiconductor planar junction is formed via local laser patterning. The fabricated planar junction in the field-effect transistors based on individual SWCNT drastically increases the photoresponse of such devices. The broadband photoresponsivity of the two-photon oxidized structures reaches the value of 2 × 107 A W−1 per single SWCNT at 1 V bias voltage. The SWCNT-based transistors with induced metal/semiconductor planar junction can be applied to detect extremely small light intensities with high spatial resolution in photovoltaics, integrated circuits, and telecommunication applications.
|
|
|
|
Feautrier, P., le Coarer, E., Espiau de Lamaestre, R., Cavalier, P., Maingault, L., Villégier, J. - C., et al. (2008). High-speed superconducting single photon detectors for innovative astronomical applications. In J. Phys.: Conf. Ser. (Vol. 97, 10).
Abstract: Superconducting Single Photon Detectors (SSPD) are now mature enough to provide extremely interesting detector performances in term of sensitivity, speed, and geometry in the visible and near infrared wavelengths. Taking advantage of recent results obtained in the Sinphonia project, the goal of our research is to demonstrate the feasibility of a new family of micro-spectrometers, called SWIFTS (Stationary Wave Integrated Fourier Transform Spectrometer), associated to an array of SSPD, the whole assembly being integrated on a monolithic sapphire substrate coupling the detectors array to a waveguide injecting the light. This unique association will create a major breakthrough in the domain of visible and infrared spectroscopy for all applications where the space and weight of the instrument is limited. SWIFTS is an innovative way to achieve very compact spectro-detectors using nano-detectors coupled to evanescent field of dielectric integrated optics. The system is sensitive to the interferogram inside the dielectric waveguide along the propagation path. Astronomical instruments will be the first application of such SSPD spectrometers. In this paper, we describes in details the fabrication process of our SSPD built at CEA/DRFMC using ultra-thin NbN epitaxial films deposited on different orientations of Sapphire substrates having state of the art superconducting characteristics. Electron beam lithography is routinely used for patterning the devices having line widths below 200 nm and down to 70 nm. An experimental set-up has been built and used to test these SSPD devices and evaluate their photon counting performances. Photon counting performances of our devices have been demonstrated with extremely low dark counts giving excellent signal to noise ratios. The extreme compactness of this concept is interesting for space spectroscopic applications. Some new astronomical applications of such concept are proposed in this paper.
|
|
