Elektrik Elektronik Mühendisliği Bölümü Yayın Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/411
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Article Entangled Two-Photon Interference(Elsevier Gmbh, 2019) Salmanogli, AhmadThis article proposes a theoretical solution to one of the original problems of the double-slit experiment, which expresses that it is impossible to identify the photon's path without disturbing it We contend that using the entangled two-photon (signal and idler photons) and inserting a double-slit into the beam of signal (idler) photon, it is possible to distinguish the path of signal (idler) photon, just by the detection of the idler (signal) photon. Basically, the signal and idler photons are highly correlated to each other due to the momentum conservation. Indeed, the photon-photon correlation originates the nonlocal interference effect, so using this effect, lets us know about which path the photon goes through, with its conjugate photon's position detection rather than its detection.Article Citation - WoS: 5Citation - Scopus: 5Plasmonic Effect on Quantum-Dot Photodetector Responsivity(Ieee-inst Electrical Electronics Engineers inc, 2019) Salmanogli, Ahmad; Gokcen, Dincer; Gecim, H. Selcuk; Selcuk Gecim, H.In this paper, we analyze and simulate the plasmonic effect on the quantum-dot photodetector responsivity. For this purpose, a plasmonic-based quantum-dot photodetector is designed in which a few quantum dots are embedded in the hot-spot regions of the plasmonic nanoparticles, wherein a high-intensity localized field is created. Notably, due to the maximum overlapping of the plasmonic field with the quantum dots at the hot spot, some of the optical characteristics of the quantum dot, particularly the spontaneous emission decay rate, are changed. This paper focuses on the engineering of the decay rate, through which we found that the quantum-dot photodetector responsivity is strongly enhanced with the order of 100 times at the visible range. For analyzing the proposed system, we first work on the plasmonic effect of the nanoparticle on the quantum-dot lifetime using the Heisenberg-Langevin equations. It is shown that by embedding the quantum dots at the hot spot of the nanoparticle, the decay rate of the quantum dot is dramatically influenced. In the following, plasmonic-quantum dot system responsivity is theoretically examined using a time-varying perturbation theory. Using this approach is necessary because the spontaneous emission cannot be analyzed with the classical methods. Consequently, it is proved that using plasmonic effect leads to enhanced photodetector responsivity, suggesting that even very small incoming signals are detectable.Article Citation - WoS: 8Citation - Scopus: 9Joint Parameter and State Estimation of the Hemodynamic Model by Iterative Extended Kalman Smoother(Elsevier Sci Ltd, 2016) Akin, Ata; Aslan, Serdar; Cemgil, Ali Taylan; Aslan, Murat Samil; Toreyin, Behcet UgurThe joint estimation of the parameters and the states of the hemodynamic model from the blood oxygen level dependent (BOLD) signal is a challenging problem. In the functional magnetic resonance imaging (fMRI) literature, quite interestingly, many proposed algorithms work only as a filtering method. This makes the estimation of hidden states and parameters less reliable compared with the algorithms that use smoothing. In standard implementations, smoothing is performed only once. However, joint state and parameter estimation can be improved substantially by iterating smoothing schemes such as the extended Kalman smoother (IEKS). In the fMRI literature, extended Kalman filtering is thought to be less accurate than standard particle filtering (PF). We compared EKF with PF and observed that the contrary is true. We improved the EKF performance by adding smoother. By iterative scheme joint hemodynamic and parameter estimation is improved substantially. We compared IEKS performance with the square-root cubature Kalman smoother (SCKS) algorithm. We show that its accuracy for the state and the parameter estimation is better and much faster than iterative SCKS. SCKS was found to be a better estimator than the dynamic expectation maximization (DEM), EKF, local linearization filter (LLF) and PP methods. We show in this paper that IEKS is a better estimator than iterative SCKS under different process and measurement noise conditions. As a result, IEKS seems to be the best method we evaluated in all aspects. (C) 2015 Elsevier Ltd. All rights reserved.Article Citation - WoS: 38Citation - Scopus: 45Propagation of Modified Bessel-Gaussian Beams in Turbulence(Elsevier Sci Ltd, 2008) Eyyuboglu, Halil Tanyer; Hardalac, FiratWe investigate the propagation characteristics of modified Bessel-Gaussian beams traveling in a turbulent atmosphere. The source beam formulation comprises a Gaussian exponential and the summation of modified Bessel functions. Based on an extended Huygens-Fresnel principle, the receiver plane intensity is formulated and solved down to a double integral stage. Source beam illustrations show that modified Bessel-Gaussian beams, except the lowest order case, will have well-like shapes. Modified Bessel-Gaussian beams with summations will experience lobe slicing and will display more or less the same profile regardless of order content. After propagating in turbulent atmosphere, it is observed that a modified Bessel-Gaussian beam will transform into a Bessel-Gaussian beam. Furthermore it is seen that modified Bessel-Gaussian beams with different Bessel function combinations, but possessing nearly the same profile, will differentiate during propagation. Increasing turbulence strength is found to accelerate the beam transformation toward the eventual Gaussian shape. (c) 2007 Elsevier Ltd. All rights reserved.Article Citation - WoS: 7Citation - Scopus: 7Plasmonic System as a Compound Eye: Image Point-Spread Function Enhancing by Entanglement(Ieee-inst Electrical Electronics Engineers inc, 2018) Salmanogli, Ahmad; Gecim, H. Selcuk; Piskin, ErhanIn this paper, we introduce a plasmonic system that can operate as a compound eye. Based on the advantages mentioned in some previous works for the compound eye, we designed a plasmonic system that contains faraway plasmonic nanoparticles (NPs) that act independently like an ommatidium in the compound eye. This plasmonic system performance is analyzed with full quantum theory by which it is theoretically proved that with the interaction of light with NPs, the scattering light, and generated phonon can be entangled due to the NPs Ohmic loss. Consequently, the quantum states of the system before, after, and during the absorption and scattering of the incident photon, were quantum mechanically subjected. By the introduced theoretical formula and modeling results, it is shown that the plasmonic system can operate similar to the compound eye, if the critical parameters, such as system's focus point, NPs scattering angle, and inter-distance between NPs are suitably designed. More importantly, due to the entanglement between the scattering light and the generated phonon, it is theoretically proved that the point-spread function is improved when the traditional lens in the compound eye is replaced by the plasmonic NPs leading to an enhanced image resolution. Finally, a simple conceptual design of the plasmonic system is presented and then a few contributed modeling results are introduced.Article Citation - WoS: 23Citation - Scopus: 23Entanglement of Optical and Microcavity Modes by Means of an Optoelectronic System(Amer Physical Soc, 2019) Salmanogli, Ahmad; Gokcen, Dincer; Gecim, H. SelcukEntanglement between optical and microwave cavity modes is a critical issue in illumination systems. Optomechanical systems are utilized to introduce coupling between the optical and microwave cavity modes. However, due to some restrictions of the optomechanical system, especially sensitivity to the thermal photon noise at room temperature, an alternative optoelectronic system is designed to address the problem. We study a method by which it may be possible to remove the mechanical part of the previous systems to minimize the thermally generated photons. Unlike optomechanical systems, in our system, the optical mode is directly coupled to the microwave cavity mode through the optoelectronic elements without employing any mechanical parts. The utilized approach leads to generating the entangled modes at room temperature. For this purpose, the dynamics of the motion of the optoelectronic system is theoretically derived using the Heisenberg-Langevin equations from which one can calculate the coupling between optical and microwave cavity modes. The direct coupling between the optical and microwave cavity modes is the most important feature and is achieved through the combination of the photodetector and a Varactor diode. Hence, by controlling the photodetector current, that is, the photocurrent, depending on the optical cavity incident wave and the Varactor diode-biased voltage, the coupling between the optical and microwave cavity modes is established. The voltage across the Varactor diode also depends on the generated photocurrent. Consequently, our results show that the coupled modes are entangled at room temperature without the requirement for any mechanical parts.Article Citation - WoS: 50Citation - Scopus: 58Application of Normal Wiggly Dual Hesitant Fuzzy Sets To Site Selection for Hydrogen Underground Storage(Pergamon-elsevier Science Ltd, 2019) Ramya, L.; Baleanu, Dumitru; Kureethara, Joseph Varghese; Annapoorani, V; Narayanamoorthy, SamayanThe hesitant fuzzy set is a mathematical tool to express multiple values in decision making. If they could not give a resolution, it is important to give priority and importance to a number of different values. Here, we propose normal wiggly dual hesitant fuzzy set (NWDHFS), as an extension of normal wiggly hesitant fuzzy set. We define a new score function of normal wiggly dual hesitant fuzzy information. The NWDHFS can express deep ideas of membership and non-membership information. In this work, we use hesitant fuzzy set to expose the deepest ideas hidden in the thought-level of the decision makers. We show that the NWDHFS can handle the hesitant fuzzy information. It expresses the deeper ideas of hesitant fuzzy set. An illustration is provided to demonstrate the practicality and effectiveness to the application of site selection of the underground storage of hydrogen. We are compelled to look for alternating fuels to suits changing weather conditions and increasing number of vehicles. This alternative fuel is necessary to control global warming and to be economically viable. Based on this, hydrogen gas is selected as a good alternative fuel. The most important statement is the saving of the selected hydrogen gas. Thus, when saving hydrogen fuel, a safe storage space must be selected. Here, we use the MCDM ideas by use of proposed NWDHFV method is to select the appropriate hydrogen underground storage location. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Article Citation - WoS: 8Citation - Scopus: 8Quantum Eye: Lattice Plasmon Effect on Quantum Fluctuations and Photon Detection(Academic Press inc Elsevier Science, 2018) Salmanogli, Ahmad; Gecim, H. SelcukIn this work, arrays of plasmonic nanoparticles coupled to a detector are designed and considered as a quantum eye. In the designed system, the plasmonic nanoparticles have a role like an ommatidium in the artificial compound eye; however, the quantum eye ommatidium acts with different functionality. To better understand this system, we analyze it with the full quantum theory, quantize lattice plasmon generated by the array of plasmonic nanoparticles, and finally derive bosonic operators using Heisenberg-Langevin equations. Moreover, we theoretically derive the radiative and non-radiative losses introduced by this system and examine lattice plasmon effect on spontaneous emission of the quantum dot (Purcell factor). The main goal of this article is to investigate the quantum eye's quantum properties such as quantum fluctuations, which is modeled and analyzed by studying the second-order correlation function. This function exhibits a significant bunching as a function of lattice plasmon optical properties. We can easily manipulate and improve the lattice plasmon optical properties, which dramatically depend on the array geometry. Finally, we study the quantum eye photon detection by a quantum measuring approach and show that the lattice plasmon has a strong effect on quantum properties after the one-count process. (C) 2018 Elsevier Inc. All rights reserved.Article Citation - WoS: 6Citation - Scopus: 6Array of Nanoparticles Coupling With Quantum-Dot: Lattice Plasmon Quantum Features(Elsevier Science Bv, 2018) Salmanogli, Ahmad; Gecim, H. SelcukIn this study, we analyze the interaction of lattice plasmon with quantum-dot in order to mainly examine the quantum features of the lattice plasmon containing the photonic/plasmonic properties. Despite optical properties of the localized plasmon, the lattice plasmon severely depends on the array geometry, which may influence its quantum features such as uncertainty and the second-order correlation function. To investigate this interaction, we consider a closed system containing an array of the plasmonic nanoparticles and quantum-dot. We analyze this system with full quantum theory by which the array electric far field is quantized and the strength coupling of the quantum-dot array is analytically calculated. Moreover, the system's dynamics are evaluated and studied via the Heisenberg-Langevin equations to attain the system optical modes. We also analytically examine the Purcell factor, which shows the effect of the lattice plasmon on the quantum-dot spontaneous emission. Finally, the lattice plasmon uncertainty and its time evolution of the second-order correlation function at different spatial points are examined. These parameters are dramatically affected by the retarded field effect of the array nanoparticles. We found a severe quantum fluctuation at points where the lattice plasmon occurs, suggesting that the lattice plasmon photons are correlated.Article Citation - WoS: 17Citation - Scopus: 16Transmittance of Multi Gaussian Optical Beams for Uplink Applications in Atmospheric Turbulence(Ieee-inst Electrical Electronics Engineers inc, 2015) Ata, Yalcin; Baykal, YahyaOn-axis slant path uplink transmittance (used in short as transmittance throughout the text) for multi Gaussian optical beam in Kolmogorov atmospheric turbulent medium is investigated. It is observed that for both the flat-topped and the annular beams, as the propagation distance, wind speed and the zenith angle increase, the transmittance decreases. The transmittance of flat-topped beams increases when the number of beams, source size or the wavelength increases. For the annular beam, when the outer/inner beam size ratio is kept constant, larger source sizes yield larger transmittance values. Transmittance of the thicker annular beams is found to be larger than the transmittance of the thinner annular beams.