Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 9Citation - Scopus: 9Graded-Index Optical Fiber Transverse-Spatial Entanglement(American Physical Society, 2020) Ekici, Çağın; Ekici, Çağın; Dinleyici, Mehmet Salih; Dinleyici, Mehmet Salih; 01. Izmir Institute of Technology; 03.05. Department of Electrical and Electronics Engineering; 03. Faculty of EngineeringWe present a study of spontaneously arisen spatially entangled photon pairs via intermodal four-wave mixing in a graded-index multimode optical fiber. Unique dispersive features of the fiber allow spectral indistinguishability of two different phase-matched processes, producing entangled pairs of spatial qubits. The bases are realized as superpositions of orthogonal transverse fiber modes having opposite parities. In particular, we take into consideration the spectral properties of the processes by examining their joint spectral amplitudes. It is shown that illuminating graded-index optical fiber with different pump wavelengths has an impact upon efficiency parameters accordingly the degree of spatial entanglement and gives rise to photon pairs with various spectral purities. Photons with higher spectral purity enable desired single-photon based interactions to take place, whereas photons with lower spectral purity exhibit hybrid entanglement in frequency and transverse mode. We also discuss Wigner function formalism and parity-displacement-based realization to characterize spatial properties of the states, as well as to verify quantum entanglement through a violation of Clauser-Horne-Shimony-Holt inequality.Article Citation - WoS: 5Citation - Scopus: 7A Practical Approach for Optical Characterization of a Film Coated on the Optical Fiber(Academic Press Inc., 2017) Ekici, Çağın; Dinleyici, Mehmet Salih; Dinleyici, Mehmet Salih; Ekici, Çağın; 01. Izmir Institute of Technology; 03.05. Department of Electrical and Electronics Engineering; 03. Faculty of EngineeringPhase Diffraction (PD) Phase Diffraction. which is a result of the interaction of light waves with a transparent object, is exploited to characterize precisely optical properties of dielectric films coated on the optical fiber without harming any feature of the sample. Typical fiber sensor applications require films coated on the side surface of the optical fiber and optical properties of that curved films are crucial for design purposes. In this study, three Polyvinyl Alcohol (PVA) films are prepared, their thicknesses are estimated based on the phase diffraction method by fitting experimental results with a mathematical model within 2.3% error. The outcomes of this practical method show good agreement with findings of the destructive Scanning Electron Microscopy (SEM) measurements. The method has the potential to allow real time monitoring abrupt changes of surrounding medium's properties and to examine coating quality (i.e. thickness uniformity) of the film.Conference Object Kırınım Yöntemi Kullanılarak Zeytinyağındaki Tağşişin Belirlenmesi(Institute of Electrical and Electronics Engineers Inc., 2017) Ekici, Çağın; Dinleyici, Mehmet Salih; Dinleyici, Mehmet Salih; Ekici, Çağın; 01. Izmir Institute of Technology; 03.05. Department of Electrical and Electronics Engineering; 03. Faculty of EngineeringBu çalışmada, faz kırınım yöntemi kullanılarak gıda sanayisindeki büyük sorunlardan biri olan zeytinyağındaki tağşişin belirlenmesi amaçlanmıştır. Örnek sıvı içerisine ideal geometriye sahip fiber optik batırılarak lazer ışığının kırınımı incelenmiştir. Kırınım alanının matematiksel ifadesi Fresnel kırınım teorisine göre nümerik olarak hesaplanmıştır. Matematiksel modelleme, deneyler sonucunda elde edilen normalleştirilmiş kırınım deseniyle karşılaştırılıp, sıvının kırıcılık indisi tahmin edilmiştir. Kırınım yönteminin sıvının kırıcılık indisi tahminindeki yüksek hassasiyetli rolü (10−5 mertebesindeki) zeytinyağındaki tağşişin belirlenmesine imkan sağlamıştır.