Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/11
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Article Citation - WoS: 7Citation - Scopus: 9Analysis of a Novel Sensor Interrogation Technique Based on Fiber Cavity Ring-Down (crd) Loop and Otdr(Academic Press Inc., 2018) Yüksel, Kıvılcım; Yılmaz, AnılWe present the analysis of a remote sensor based on fiber Cavity Ring-Down (CRD) loop interrogated by an Optical Time Domain Reflectometer (OTDR) taking into account both practical limitations and the related signal processing. A commercial OTDR is used for both pulse generation and sensor output detection. This allows obtaining a compact and simple design for intensity-based sensor applications. This novel sensor interrogation approach is experimentally demonstrated by placing a variable attenuator inside the fiber loop that mimics a sensor head.Article Development of a Phase-Otdr Interrogator Based on Coherent Detection Scheme(Uludağ Üniversitesi, 2018) Yüksel, Kıvılcım; Jason, Johan; Wuilpart, MarcWe present in this work, the experimental demonstration of a phase-sensitive Optical Time- Domain Reflectometer (phase-OTDR) having coherent detection scheme. An analysis algorithm has also been developed to calculate amplitude and phase evolution of the experimental phase-OTDR traces. The efficiency of the analysis algorithm to determine the position of the applied vibration has been verified for a single and two simultaneous vibrations. The slow-time analysis results show a good agreement with the mathematical calculations discussed in the paper. This work could have a technological implication in many fields such as distributed vibration sensor for railway monitoring applications.Article Experimental Investigation of Refractive Index Measurement of Common Solvents and Aqueous Solutions in the Infrared Wavelengths(Balkan Yayın, 2018) İde, Cansu; Yüksel Aldoğan, Kıvılcım; Yüksel, KıvılcımWe proposed and experimentally demonstrated a fast and simple technique to measure refractive index of liquids. A commercial Optical Time-Domain Reflectometer (OTDR) was implemented for interrogating sensor tips from a remote location. The system uses Fresnel reflected light from standard single mode fiber tips as sensing points without requiring any chemical coating, delicate fiber components, and/or sophisticated architecture at the sensor head. We reported new measurements of refractive indices of common solvents and solutions at both 1550 nm and 1625 nm. The precision of the proposed measurement system was found to be in the order of 10-4. The experimental results have been validated by the way of theoretical calculations.Conference Object Rayleigh-Based Optical Reflectometry Techniques for Distributed Sensing Applications(Selçuk Üniversitesi, 2018) Yüksel, KıvılcımIn this paper, we discuss the operation principles, sensing mechanisms, challenges and application areas of the optical reflectometry techniques exploiting Rayleigh scattering phenomenon, considering both time- and frequency-domain schemes. Among various distributed optical fiber sensor (DOFS) systems interrogated by optical reflectometry techniques, a special emphasis was given, in this paper to distributed acoustic sensor (DAS) interrogation methods. Recent progresses obtained through our research collaborations are also presented.Conference Object Laboratory Evaluation of a Phase-Otdr Setup for Railway Monitoring Applications(Institute of Electrical and Electronics Engineers Inc., 2017) Jason, J.; Yüksel, Kıvılcım; Wuilpart, MarcPhase-sensitive optical time-domain reflectometry (phase-OTDR) has recently drawn increased attention for applications within the railway transportation sector. In this paper we present a laboratory approach to demonstrate the feasibility of an interrogator of vibrations along railways by means of fiber-optic cables. Contrary to the common use of piezo-electric phase modulators in laboratory setups, a vibration shaker is used to excite a plastic tube to which the fiber is attached. Measurement of event position and frequency is demonstrated in a range up to 7000 Hz.Conference Object Citation - WoS: 5Centralised Optical Monitoring of Tree-Structured Passive Optical Networks Using a Raman-Assisted Otdr(Institute of Electrical and Electronics Engineers Inc., 2007) Yüksel, Kıvılcım; Letheux, S.; Grillet, A.; Wuilpart, Marc; Giannone, D.; Hancq, J.; Ravet, G.; Mégret, PatriceMonitoring of tree-structured Passive Optical Networks from a central office is difficult to achieve using a standard OTDR. Switchable reflective elements placed at the ONU can help to discriminate between the branches. In parallel, a Raman assisted OTDR is shown to increase the dynamic range of the reflectometry measurement, thus enabling to detect more faults in the network, and especially fibre breaks after the splitter. ©2007 IEEE.Conference Object Citation - WoS: 39Optical Layer Monitoring in Passive Optical Networks (pons): a Review(Institute of Electrical and Electronics Engineers Inc., 2008) Yüksel, Kıvılcım; Moeyaert, Véronique; Wuilpart, Marc; Mégret, PatriceMotivations, challenges and requirements of optical layer monitoring in PONs are discussed. An exhaustive review of monitoring systems is given considering both Time-Division Multiplexed PON (TDM-PON) and Wavelength-Division Multiplexed PON (WDM-PON) cases. © 2008 IEEE.Article Citation - WoS: 28Citation - Scopus: 30Optical Fiber Sensor System for Remote and Multi-Point Refractive Index Measurement(Elsevier Ltd., 2016) Yüksel, KıvılcımA Fresnel-reflection-based RI sensor using SMF fiber tips as sensing points interrogated by multi-wavelength OTDR from a distant location (up to several tens of kilometers) has been reported. The advantage of the system compared to previous work is that the distance between sensor points is not limited by the spatial resolution of OTDR. Experimental work demonstrated that the proposed sensor is capable of measuring refractive index of liquid chemicals with a precision of 1.7 × 10−4. This sensor prototype have strong conveniences (simple installation requirements, fast response and reliability in harsh environment) compared to previous Fresnel-based RI sensors which makes it a very good option for environmental monitoring systems. © 2016 Elsevier B.V.