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| Author | Sáysz, Wojciech; Guziewicz, Marek; Bar, Jan; Wegrzecki, Maciej; Grabiec, Piotr; Grodecki, Remigiusz; Wegrzecka, Iwona; Zwiller, Val; Milosnaya, Irina; Voronov, Boris; Gol’tsman, Gregory; Kitaygorsky, Jen; Sobolewski, Roman | ||||
| Title | Superconducting NbN nanostructures for single photon quantum detectors | Type | Abstract | ||
| Year | 2008 | Publication | Proc. 7-th Int. Conf. Ion Implantation and Other Applications of Ions and Electrons | Abbreviated Journal | Proc. 7-th Int. Conf. Ion Implantation and Other Applications of Ions and Electrons |
| Volume | Issue | Pages | 160 | ||
| Keywords | SSPD, SNSPD | ||||
Abstract  |
Practical quantum systems such as quantum communication (QC) or quantum measurement systems require detectors with high speed, high sensitivity, high quantum efficiency (QE), and short deadtimes along with precise timing characteristics and low dark counts. Superconducting single photon detectors (SSPDs) based on ultrathin meander type NbN nanostripes (operated at T=2-5K) are a new and highly promising type of devices fulfilling above requirements. In this paper we present results of the SSPDs nanostructure technological optimization. The base for our detector is thin-film (4nm) NbN layer deposited on 350- P m-thick sapphire substrate The active element of the detector is a meander- nanostructure made of 4-nm-thick and 100-nm-wide NbN stripe, covering 10 u 10 P m 2 area with the filling factor ~0,5. The NbN superconducting films were deposited on sapphire substrates by DC reactive magnetron sputtering whereas the meander element of the detector was patterned by the direct electron-beam lithography followed by reactive-ion etching. To enhance the SSPD efficiency at Ȝ = 1.55 P m, we have performed an approach to increase the absorption of the detector by integrating it with optical resonant cavity. An optical microcavity optimized for absorption of 1.55 P m photons was designed as an one-mirror resonator consisting of a Ȝ/4 dielectric layer and a metallic mirror. The microcavity was deposited on the top of the NbN SSPD meander. The resonator was formed by the dielectric SiO 2 layer and metal mirror made of gold or palladium. Microcavity layers were deposited using a magnetron sputtering system. | ||||
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| Notes | Approved | no | |||
| Call Number | Serial | 1409 | |||
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| Author | Vachtomin, Y. B.; Antipov, S. V.; Maslennikov, S. N.; Smirnov, K. V.; Polyakov, S. L.; Zhang, W.; Svechnikov, S. I.; Kaurova, N. S.; Grishina, E. V.; Voronov, B. M.; Gol’tsman, G. N. | ||||
| Title | Quasioptical hot electron bolometer mixers based on thin NBN films for terahertz region | Type | Conference Article | ||
| Year | 2006 | Publication | Proc. 16th Int. Crimean Microwave and Telecommunication Technology | Abbreviated Journal | Proc. 16th Int. Crimean Microwave and Telecommunication Technology |
| Volume | 2 | Issue | Pages | 688-689 | |
| Keywords | NbN HEB mixers | ||||
| Abstract |
Presented in this paper are the performances of HEB mixers based on 2-3.5 nm thick NbN films integrated with log-periodic spiral antenna. Double side-band receiver noise temperature values are 1300 K and 3100 K at 2.5 THz and at 3.8 THz, respectively. Mixer gain bandwidth is 5.2 GHz. Local oscillator power is 1-3 muW for mixers with different active area | ||||
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| Language | Russian | Summary Language | Original Title | ||
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| Notes | Approved | no | |||
| Call Number | Serial | 1445 | |||
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| Author | Smirnov, K.; Korneev, A.; Minaeva, O.; Divochij, A.; Rubtsova, I.; Antipov, A.; Ryabchun, S.; Okunev, O.; Milostnaya, I.; Chulkova, G.; Voronov, B.; Kaurova, N.; Seleznev, V.; Korotetskaya, Y.; Gol’tsman, G. | ||||
| Title | Superconducting single-photon detector for near- and middle IR wavelength range | Type | Conference Article | ||
| Year | 2006 | Publication | Proc. 16th Int. Crimean Microwave and Telecommunication Technology | Abbreviated Journal | Proc. 16th Int. Crimean Microwave and Telecommunication Technology |
| Volume | 2 | Issue | Pages | 684-685 | |
| Keywords | NbN SSPD, SNSPD | ||||
| Abstract |
Presented in this paper are the results of research of NbN-film superconducting single-photon detector. At 2 K temperature, quantum efficiency in the visible light (0.56 mum) reaches 30-40 %. With the wavelength increase quantum efficiency decreases and comes to 20% at 1.55 mum and 0.02% at 5.6 mum. Minimum dark counts rate is 2times10-4s-1. The jitter of detector is 35 ps. The detector was successfully implemented for integrated circuits non-invasive optical testing. It is also perspective for quantum cryptography systems | ||||
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| Language | Russian | Summary Language | Original Title | ||
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| Notes | Approved | no | |||
| Call Number | Serial | 1447 | |||
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| Author | Iomdina, E. N.; Seliverstov, S.; Sianosyan, A.; Teplyakova, K.; Rusova, A.; Goltsman, G. | ||||
| Title | The prospects of using the radiation for the assessment of corneal and scleral hydration | Type | Abstract | ||
| Year | 2016 | Publication | Acta Ophthalmol. | Abbreviated Journal | Acta Ophthalmol. |
| Volume | 94 | Issue | Pages | ||
| Keywords | BWO, avalanche transit‐time diode, medicine, biology | ||||
| Abstract |
Purpose An adequate water balance (hydration extent) is one of the basic factors of normal eye function, including its external shells – the cornea and the sclera. THz systems creating images in reflected beams are likely to become ideal instruments of noninvasive testing of corneal and scleral hydration degree as THz radiation is highly sensitive to water content. The paper aims at studying the transmittance and reflectance spectra of the cornea and the sclera of rabbit and human eyes, as well as those of the whole rabbit eye, in the frequency range of 0.13–0.32 THz. Methods The experiments were carried out on 3 corneas and 3 rabbit scleras, 2 whole rabbit eyes, and 3 human healthy adult scleras using a specially developed THz system based on reliable and easy‐to‐use continuous wave sources: a backward‐wave oscillator and an avalanche transit‐time diode. Results The transmittance spectra of the cornea and the sclera and the dependence of the reflection coefficient of these tissues in THz range on water percentage content were determined. Comparison of the rabbit cornea hydrated from 73.2% to 76.3% concentration by mass demonstrated an approximately linear relationship between THz reflectivity and water concentration. The decrease of free water concentration by 1% leads to a drop of the reflectance coefficient by 13%. The parameters studied displayed noticeable differences between the sclera and the cornea of rabbits and between rabbit sclera and human sclera. Conclusions Preliminary results demonstrate that the proposed technique, based on continuous THz radiation, may be used to create a device for noninvasive testing of corneal and scleral hydration, which has good potential of wide‐scale practical application. The work was supported by the Russian Foundation of Basic Research (grant No.15‐29‐03843) |
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| ISSN | 1755375X | ISBN | Medium | ||
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| Notes | Approved | no | |||
| Call Number | Serial | 1333 | |||
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| Author | Lobanov, Y. V.; Vakhtomin, Y. B.; Pentin, I. V.; Rosental, V. A.; Smirnov, K. V.; Goltsman, G. N.; Volkov, O. Y.; Dyuzhikov, I. N.; Galiev, R. R.; Ponomarev, D. S.; Khabibullin, R. A. | ||||
| Title | Time-resolved measurements of light–current characteristic and mode competition in pulsed THz quantum cascade laser | Type | Journal Article | ||
| Year | 2021 | Publication | Optical Engineering | Abbreviated Journal | Optical Engineering |
| Volume | 60 | Issue | 8 | Pages | 1-8 |
| Keywords | HEB, terahertz pulse generation, terahertz pulse detection, QCL, quantum cascade laser, superconducting hot electron bolometer | ||||
| Abstract |
Quantum cascade lasers (QCL) are widely adopted as prominent and easy-to-use solid-state sources of terahertz radiation. Yet some applications require generation and detection of very sharp and narrow terahertz-range pulses with a specific spectral composition. We have studied time-resolved light-current (L–I) characteristics of multimode THz QCL operated with a fast ramp of the injection current. Detection of THz pulses was carried out using an NbN superconducting hot-electron bolometer with the time constant of the order of 1 ns while the laser bias current was swept during a single driving pulse. A nonmonotonic behavior of the L–I characteristic with several visually separated subpeaks was found. This behavior is associated with the mode competition in THz QCL cavity, which we confirm by L–I measurements with use of an external Fabry–Perot interferometer for a discrete mode selection. We also have demonstrated the possibility to control the L–I shape with suppression of one of the subpeaks by simply adjusting the off-axis parabolic mirror for optimal optical alignment for one of the laser modes. The developed technique paves the way for rapid characterization of pulsed THz QCLs for further studies of the possibilities of using this approach in remote sensing. | ||||
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| Notes | Approved | no | |||
| Call Number | 10.1117/1.Oe.60.8.082019 | Serial | 1260 | ||
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