Person: DURAK, Kadir
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Kadir
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DURAK
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ArticlePublication Metadata only Effect of photon statistics on vacuum fluctuations based QRNG(IOP Publishing, 2021-06) Dandaşi, Abdulrahman; Özel, Helin; Hasekioglu, O.; Durak, Kadir; Electrical & Electronics Engineering; DURAK, Kadir; Dandaşi, Abdulrahman; Özel, HelinThe speed of quantum random number generators (QRNGs) is a major concern for practical applications. In this work, we introduce scattering as a method to enhance the randomness characteristics of the entropy source. This method allows optical bit extraction with a faster sampling rate without compromising the randomness quality compared to the coherent source based balanced homodyne detection. Scattering is a probabilistic phenomenon which increases the chaotic behaviour of coherent sources. It broadens the distribution of photon statistics and makes it super-Poissonian. We show that a signal with super-Poissonian distribution has better randomness compared to a Poissonian one, indicated by their autocorrelation characteristics and the randomness test results. The use of scattering mechanisms as an entropy source eases the miniaturization of QRNGs, it also makes them compatible and adaptable to existing technologies.Conference ObjectPublication Metadata only Single photon detection with silicon-based avalanche photodiode(SPIE, 2023) Yerli, Burcu; Eraydın, Can; Cinkaya, H.; Durak, Kadir; Electrical & Electronics Engineering; DURAK, Kadir; Yerli, Burcu; Eraydın, CanThanks to the significant advances in quantum technologies, the use of single photon detectors (SPDs) is becoming increasingly common. As a result of the excellent photodetection performance of these detectors, they have been utilized in a wide range of fields such as quantum cryptography, astronomy, spectroscopy, and medical applications. There is no doubt that improvements in the performance of these detectors will open new paths to their multidisciplinary applications. Over the years, several different types of SPDs have been developed, such as photomultiplier tubes based on vacuum tubes, avalanche photodiodes (APDs) based on semiconductors, or nanowires based on superconducting technology. Any of these technologies, which are also commercially offered by many companies, has been used according to their advantages and disadvantages for intended applications by making a trade-off. At that point, SPDs based on Silicon APD technology have many advantages including low voltage operation, high reliability, simple electronic requirements, and high detection efficiency. In this study, the TO-8 SAP500 series Silicon APD provided by Laser Component was preferred, and the driving circuit was designed for visible-range sensing applications. The quenching and thermoelectric cooling circuit designs were presented, and the performance of the detector was analyzed according to some important parameters. Our motivation is to investigate the CubeSat compatibility of the detector for space applications.ArticlePublication Metadata only Development of an aerial interface for extraction of the electrodynamic fingerprints of the single-photon detectors(Wiley, 2021-12) Karamzadeh, S.; Durak, Kadir; Jam, Naser Chamani; Rafiei, V.; Awad, B.; Electrical & Electronics Engineering; DURAK, Kadir; Jam, Naser ChamaniIn this study, a novel structure of semi array of antipodal Vivaldi antenna is designed to extract the RF radiations from the single-photon detectors in a quantum key distribution system. The proposed antenna covers a frequency range from 2 to 12 GHz with an average gain of 12.5 dBi which has improved by a lens structure. In the first step, the design proceeding of the antenna has been discussed, and then, some of the unique futures of the proposed antenna which promoted it to use in quantum attack systems, such as linear momentum, a good Envelope Correlation Coefficient, and Gaussian pulse response, are discussed.ArticlePublication Metadata only Tracking capacitance of liquid crystal devices to improve polarization rotation accuracy(Optical Society of America, 2017-08-21) Chandrasekara, R.; Durak, Kadir; Ling, A.; Electrical & Electronics Engineering; DURAK, KadirWe report a capacitance tracking method for achieving arbitrary polarization rotation from nematic liquid crystals. By locking to the unique capacitance associated with the molecular orientation, any polarization rotation can be achieved with improved accuracy over a wide temperature range. A modified relaxation oscillator circuit that can simultaneously determine the capacitance and drive the rotator is presented.ArticlePublication Open Access Entanglement demonstration on board a nano-satellite(The Optical Society, 2020-07-20) Villar, A.; Lohrmann, A.; Bai, X.; Vergoossen, T.; Bedington, R.; Perumangatt, C.; Lim, H. Y.; Islam, T.; Reezwana, A.; Tang, Z.; Chandrasekara, R.; Sachidananda, S.; Durak, Kadir; Wildfeuer, C. F.; Griffin, D.; Oi, D. K. L.; Ling, A.; Electrical & Electronics Engineering; DURAK, KadirGlobal quantum networks for secure communication can be realized using large fleets of satellites distributing entangled photon pairs between ground-based nodes. Because the cost of a satellite depends on its size, the smallest satellites will be most cost-effective. This Letter describes a miniaturized, polarization entangled, photon-pair source operating on board a nano-satellite. The source violates Bell's inequality with a Clauser-Horne-Shimony-Holt parameter of 2.60 +/- 0.06. This source can be combined with optical link technologies to enable future quantum communication nano-satellite missions.Conference ObjectPublication Metadata only Entanglement demonstration on board a nano-satellite(Optica Publishing Group, 2020) Villar, A.; Lohrmann, A.; Bai, X.; Vergoosen, T.; Bedington, R.; Perumangatt, C.; Lim, H. Y.; Islam, T.; Reezwana, A.; Tang, Z.; Chandrasekara, R.; Sachidananda, S.; Durak, Kadir; Wildfeuer, C. F.; Griffin, D.; Oi, D. K. L.; Ling, A.; Electrical & Electronics Engineering; DURAK, KadirPolarization entangled photon-pairs are generated and detected onboard a 3U CubeSat in low-Earth orbit that violate Bell’s inequality with a CHSH parameter of 2.60 ± 0.06. These results pave the way for space-based quantum networks.Conference ObjectPublication Metadata only Object tracking and identification by quantum radar(SPIE, 2019) Durak, Kadir; Jam, Naser Chamani; Dindar, Çağrı; Electrical & Electronics Engineering; Rarity, J. G.; Kimata, M.; Shaw, J. A.; Valenta, C. R.; DURAK, Kadir; Jam, Naser Chamanı; Dindar, ÇağrıQuantum Radar is a promising technology that could have a strong impact on the civilian and military realms. In this study we introduce a new concept design for implementing a Quantum Radar, based on the time and polarization correlations of the entangled photons for detection and identification and tracking of high-speed targets. The design is focused on extracting high resolution details of the target with precision timing of entangled photons that provides important operational capabilities like distinguishing a target from a decoy. The quantum entanglement properties guarantee the legitimacy of the photons captured by the search telescope. Time correlations of the photon detection events can be extracted via cross-correlation operation between two sets of photon detection time-tags for the entangled photons. The fact that the wavelengths of the entangled photons can be tuned also makes the Quantum Radar concept an enticing candidate for tracking stealth objects. We present the proof-of-principle test results of the Quantum Radar and discuss the technical challenges and limitations of the design.Conference ObjectPublication Metadata only PYNQ-based rapid FPGA implementation of quantum key distribution(IEEE, 2021) Bilgin, Yiğit; Tesfay, Shewıt Weldu; İpek, Seçkin; Uğurdağ, Hasan Fatih; Durak, Kadir; Gören, S.; Electrical & Electronics Engineering; UĞURDAĞ, Hasan Fatih; DURAK, Kadir; Bilgin, YiğitIn this paper, we present a real-time Quantum Key Distribution (QKD) implementation on Field Programmable Gate Arrays (FPGAs) for secure communication. We propose a novel methodology with a Python-based programming interface for rapid development on FPGA. Our methodology revolves three phases of development. In the first phase, a reference model of an entangled photon source and the proposed QKD system are developed in Python. Next, the reference model is passed through a thorough verification phase. In the second phase, the reference model is implemented on the Processing System (PS) part of the FPGA. Finally in the third phase, the computationally intensive part of the QKD architecture is off-loaded on to the Programmable Logic (PL) part of the FPGA for acceleration. We employ PYNQ framework in our QKD development and successfully combine the convenience of Python productivity with FPGA based acceleration.Conference ObjectPublication Metadata only Down-conversion emission profile characterisation via camera(Optica Publishing Group, 2020-12-14) Kuniyil, Hashir Puthiyapurayil; Durak, Kadir; Electrical & Electronics Engineering; DURAK, Kadir; Kuniyil, Hashir PuthiyapurayilWe present a method to improve the brightness and collection efficiency of the spontaneous parametric down-conversion source by monitoring the mode shape using camera and correcting it with collection optics.ArticlePublication Open Access Quantum signatures in a quadratic optomechanical heat engine with an atom in a tapered trap(Optica Publishing Group, 2022-12) Izadyari, M.; Öncü, Mehmet; Durak, Kadir; Müstecaplioğlu, Ö. E.; Electrical & Electronics Engineering; DURAK, Kadir; Öncü, MehmetWe investigate how quantum signatures can emerge in a single atom heat engine consisting of an atom confined in a tapered trap and subjected to hot and cold thermal reservoirs. A similar system was realized experimentally in Science 352, 325 (2016). We model such a system using a quadratic optomechanical model and identify an effective Otto cycle in the system’s dynamics. We compare the engine’s performance in quantum and classical regimes by evaluating the power dissipated. We find that lowering the temperature is insufficient to make the single atom engine in Science 352, 325 (2016) a genuine quantum-enhanced heat engine. We show that it is necessary to make the trap more asymmetric and confined to ensure that quantum correlations cause an enhancement in the power output.