Marksteiner, M., Divochiy, A., Sclafani, M., Haslinger, P., Ulbricht, H., Korneev, A., et al. (2009). A superconducting NbN detector for neutral nanoparticles. Nanotechnol., 20(45), 455501.
Abstract: We present a proof-of-principle study of superconducting single photon detectors (SSPD) for the detection of individual neutral molecules/nanoparticles at low energies. The new detector is applied to characterize a laser desorption source for biomolecules and allows retrieval of the arrival time distribution of a pulsed molecular beam containing the amino acid tryptophan, the polypeptide gramicidin as well as insulin, myoglobin and hemoglobin. We discuss the experimental evidence that the detector is actually sensitive to isolated neutral particles.
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Fiore, A., Marsili, F., Bitauld, D., Gaggero, A., Leoni, R., Mattioli, F., et al. (2009). Counting photons using a nanonetwork of superconducting wires. In M. Cheng (Ed.), Nano-Net (pp. 120–122). Berlin, Heidelberg: Springer Berlin Heidelberg.
Abstract: We show how the parallel connection of photo-sensitive superconducting nanowires can be used to count the number of photons in an optical pulse, down to the single-photon level. Using this principle we demonstrate photon-number resolving detectors with unprecedented sensitivity and speed at telecommunication wavelengths.
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Venkatasubramanian, C., Cabarcos, O. M., Allara, D. L. H., Mark W., & Ashok, S. (2009). Correlation of temperature response and structure of annealed VOx thin films for IR detector applications. J. Vac. Sci. Technol. A, 27(4), 6.
Abstract: The effects of thermal annealing on vanadium oxide (VOx) thin films prepared by pulsed-dc magnetron sputtering were studied to explore methods of improving the efficiency of uncooled IR imaging microbolometers, particularly with respect to maximizing the temperature coefficients of resistance (TCR) (typically ~2%) while minimizing resistivity values (typically 0.05–5 Ω cm). Since high TCR values are usually associated with high resistivities, the experiments were designed to find processing conditions that provide an optimal balance in these properties and to then determine the underlying structural correlations which would enable rational design of thin films for this specific application. VOx films of different compositions were deposited by pulsed-dc reactive sputtering from a vanadium target at different oxygen flow rates. The deposited films were further modified by annealing in inert (nitrogen) and oxidizing (oxygen) atmospheres at four different temperatures for 10, 20, or 30 min at a time. The resistivities of the as-deposited films ranged from 0.2 to 13 Ω cm and the TCR values varied from –1.6% to –2.2%. Depending on the exact annealing conditions, several orders of magnitude change in resistance and significant variations in TCR were observed. Optimal results were obtained with annealing in a nitrogen atmosphere. Structural characterization by x-ray diffraction, field emission scanning electron microscopy, atomic force microscopy, and Raman spectroscopy indicated changes in the film crystallinity and phase for annealing conditions over 300 °C with the onset and extent of the changes dependent on which annealing atmosphere was used.
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Benford, D., Moseley, H., & Zmuidzinas, J. (2009). Direct detectors for the Einstein inflation probe. In J. Phys.: Conf. Ser. (Vol. 155, 012001 (1 to 49)).
Abstract: Here we review the principles of operation, history, present status, and future prospects for the primary candidate detectors for Cosmic Microwave Background (CMB) polarization studies. The three detector types we will discuss are semiconductor-based bolometers, superconducting transition edge sensor (TES) bolometer, and Microwave Kinetic Inductance Detectors (MKIDs). All of these detector types can provide the sensitivity to permit background-limited measurements of the CMB, but the ultimate selection of detectors will be largely determined by the ease of production and reliability of large arrays of such detectors. This paper describes the present state of development of these detectors, efforts to integrate them into large arrays, and the detector system developments necessary to enable a space CMB polarization mission.
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Goltsman, G., Korneev, A., Divochiy, A., Minaeva, O., Tarkhov, M., Kaurova, N., et al. (2009). Ultrafast superconducting single-photon detector. J. Modern Opt., 56(15), 1670–1680.
Abstract: The state-of-the-art of the NbN nanowire superconducting single-photon detector technology (SSPD) is presented. The SSPDs exhibit excellent performance at 2 K temperature: 30% quantum efficiency from visible to infrared, negligible dark count rate, single-photon sensitivity up to 5.6 µm. The recent achievements in the development of GHz counting rate devices with photon-number resolving capability is presented.
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Scheel, S. (2009). Single-photon sources–an introduction. J. Modern Opt., 56(2-3), 141–160.
Abstract: This review surveys the physical principles and recent developments in manufacturing single-photon sources. Special emphasis is placed on important potential applications such as linear optical quantum computing (LOQC), quantum key distribution (QKD) and quantum metrology that drive the development of these sources of single photons. We discuss the quantum-mechanical properties of light prepared in a quantum state of definite photon number and compare it with coherent light that shows a Poissonian distribution of photon numbers. We examine how the single-photon fidelity directly influences the ability to transmit secure quantum bits over a predefined distance. The theoretical description of modified spontaneous decay, the main principle behind single-photon generation, provides the background for many experimental implementations such as those using microresonators or pillar microcavities. The main alternative way to generate single photons using postselection of entangled photon pairs from parametric down-conversion, will be discussed. We concentrate on describing the underlying physical principles and we will point out limitations and open problems associated with single-photon production.
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Karpowicz, N., Lu, X., & Zhang, X. - C. (2009). Terahertz gas photonics. J. Modern Opt., 56(10), 1137–1150.
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.
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Polyakov, S. V., & Migdalla, A. L. (2009). Quantum radiometry. J. Modern Opt., 56(9), 1045–1052.
Abstract: We review radiometric techniques that take advantage of photon counting and stem from the quantum laws of nature. We present a brief history of metrological experiments and review the current state of experimental quantum radiometry.
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Dauler, E., Kerman, A., Robinson, B., Yang, J., Voronov, B., Goltsman, G., et al. (2009). Photon-number-resolution with sub-30-ps timing using multi-element superconducting nanowire single photon detectors. J. Modern Opt., 56(2), 364–373.
Abstract: A photon-number-resolving detector based on a four-element superconducting nanowire single photon detector is demonstrated to have sub-30-ps resolution in measuring the arrival time of individual photons. This detector can be used to characterize the photon statistics of non-pulsed light sources and to mitigate dead-time effects in high-speed photon counting applications. Furthermore, a 25% system detection efficiency at 1550 nm was demonstrated, making the detector useful for both low-flux source characterization and high-speed photon-counting and quantum communication applications. The design, fabrication and testing of this detector are described, and a comparison between the measured and theoretical performance is presented.
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Marsili, F., Bitauld, D., Fiore, A., Gaggero, A., Leoni, R., Mattioli, F., et al. (2009). Superconducting parallel nanowire detector with photon number resolving functionality. J. Modern Opt., 56(2-3), 334–344.
Abstract: We present a new photon number resolving detector (PNR), the Parallel Nanowire Detector (PND), which uses spatial multiplexing on a subwavelength scale to provide a single electrical output proportional to the photon number. The basic structure of the PND is the parallel connection of several NbN superconducting nanowires (100 nm-wide, few nm-thick), folded in a meander pattern. Electrical and optical equivalents of the device were developed in order to gain insight on its working principle. PNDs were fabricated on 3-4 nm thick NbN films grown on sapphire (substrate temperature TS=900C) or MgO (TS=400C) substrates by reactive magnetron sputtering in an Ar/N2 gas mixture. The device performance was characterized in terms of speed and sensitivity. The photoresponse shows a full width at half maximum (FWHM) as low as 660ps. PNDs showed counting performance at 80 MHz repetition rate. Building the histograms of the photoresponse peak, no multiplication noise buildup is observable and a one photon quantum efficiency can be estimated to be QE=3% (at 700 nm wavelength and 4.2 K temperature). The PND significantly outperforms existing PNR detectors in terms of simplicity, sensitivity, speed, and multiplication noise.
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