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Shcherbatenko, M. L., Elezov, M. S., Goltsman, G. N., & Sych, D. V. (2020). Sub-shot-noise-limited fiber-optic quantum receiver. Phys. Rev. A, 101(3), 032306 (1 to 5).
Abstract: We experimentally demonstrate a quantum receiver based on the Kennedy scheme for discrimination between two phase-modulated weak coherent states. The receiver is assembled entirely from standard fiber-optic elements and operates at a conventional telecom wavelength of 1.55 μm. The local oscillator and the signal are transmitted through different optical fibers, and the displaced signal is measured with a high-efficiency superconducting nanowire single-photon detector. We show the discrimination error rate is two times below that of a shot-noise-limited receiver with the same system detection efficiency.
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Bakhvalova, T., Belkin, M. E., Kovalyuk, V. V., Prokhodtcov, A. I., Goltsman, G. N., & Sigov, A. S. (2019). Studying key principles for design and fabrication of silicon photonic-based beamforming networks. In PIERS-Spring (pp. 745–751).
Abstract: In the paper, we address key principles for computer-aided design and fabrication of silicon-photonics-based optical beamforming network selecting the optimal approach by simulation and experimental results. To clarify the consideration, the study is conducted on the example of a widely used binary switchable silicon-nitride optical beamforming network based on TriPleX platform. Comparison of simulation results and experimental studies of the prototype shows that the relative error due to technological imperfections does not exceed 3%. According to the estimation, such an error introduces insignificant distortion in the radiation pattern of the referred antenna array.
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Iomdina, E. N., Goltsman, G. N., Seliverstov, S. V., Sianosyan, A. A., Teplyakova, K. O., & Rusova, A. A. (2016). Study of transmittance and reflectance spectra of the cornea and the sclera in the THz frequency range. J. Biomed. Opt., 21(9), 97002 (1 to 5).
Abstract: 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. Adequate control of corneal and scleral hydration is very important for early diagnosis of a variety of eye diseases, stating indications for and contraindications against keratorefractive surgeries and the choice of contact lens correction solutions. THz systems of creating images in reflected beams are likely to become ideal instruments of noninvasive control of corneal and scleral hydration degrees. This paper reports on the results of a study involving transmittance and reflectance spectra for the cornea and the sclera of rabbit and human eyes, as well as those of the rabbit eye, in the frequency range of 0.13 to 0.32 THz. The dependence of the reflectance coefficient of these tissues on water mass percentage content was determined. The experiments were performed on three corneas, three rabbit scleras, two rabbit eyes, and three human scleras. The preliminary results demonstrate that the proposed technique, based on the use of a continuous THz radiation, may be utilized to create a device for noninvasive control of corneal and scleral hydration, which has clear potential of broad practical application.
Keywords: BWO, IMPATT diode, Schottky diode, medicine, animals, cornea, physiology, humans, rabbits, sclera diagnostic imaging, physiology
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Ryabchun, S., Tong, C. - Y. E., Blundell, R., Kimberk, R., & Gol'tsman, G. (2007). Study of the effect of microwave radiation on the operation of HEB mixers in the terahertz frequency range. IEEE Trans. Appl. Supercond., 17(2), 391–394.
Abstract: We have investigated the effect of injecting microwave radiation, with a frequency much lower than that corresponding to the energy gap of the superconductor, on the performance of the hot-electron bolometer mixer incorporated into a THz heterodyne receiver. More specifically, we show that exposing the mixer to microwave radiation does not cause a significant rise of the receiver noise temperature and fall of the mixer conversion gain so long as the microwave power is a small fraction of local oscillator power. The injection of a small, but controlled amount of microwave power therefore enables active compensation of local oscillator power and coupling fluctuations which can significantly degrade the gain stability of hot electron bolometer mixer receivers.
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Elmanova, A., An, P., Kovalyuk, V., Golikov, A., Elmanov, I., & Goltsman, G. (2020). Study of silicon nitride O-ring resonator for gas-sensing applications. In J. Phys.: Conf. Ser. (Vol. 1695, 012124).
Abstract: In this work, we experimentally studied the influence of different gaseous surroundings on silicon nitride O-ring resonator transmission. We compared the obtained results with numerical calculations and theoretical analysis and found a good agreement between them. Our results have a great potential for gas sensing applications, where a compact footprint and high efficiency are desired simultaneously.
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