Browsing by Author "Ceylan, Abdullah"

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1974 Kıbrıs Barış Harekâtı : sözlü kaynaklar üzerinden 1974 Kıbrıs Barış Harekâtı’nın Kıbrıs toplumu üzerindeki sosyal ve ekonomik etkileri
(Bilkent University, 2014) Şahin, Ümitcan; Bartan, Burak; Ataman, Zuhal Dilek; Ceylan, Abdullah; Yeşildal, Kaan
Open Access
Fiber-optic gyroscope for the suppression of a Faraday-effect-induced bias error
(Optica, 2021-09-01) Yertutanol, Aylin; Akçaalan, Önder; Öğüt, Serdar; Özbay, Ekmel; Ceylan, Abdullah
Inertial rotation sensors, interferometric fiber-optic gyro scopes (IFOGs), are widely used in military and industrial applications due to their high sensitivity and stability. In this Letter, a new, to the best of our knowledge, fiber coil design is proposed to reduce magnetic field sensitivity without adding any optical components or electronic algo rithms to the IFOG system. It is shown that this design can be applied without disturbing the simplest IFOG struc ture. Considering the fact that the magnetic field has an invertible effect on polarization, the compensation of the Faraday-effect-induced bias error has been demonstrated theoretically and experimentally by allowing two different polarizations to travel inside the fiber coil. According to the experimental results, the bias error was reduced approxi mately 20 times from ± 9.6◦ /h/mT to ± 0.5◦ /h/mT.
Open Access
Optimization of the annealed proton exchange method with controlled annealing for multifunctional integrated optical chip production
(Optica, 2022-10-20) Asık, Fatma Yasemin; Gökkavas, Mutlu; Öztekin, Evren; Karagöz, Ercan; Ceylan, Abdullah; Özbay, Ekmel
The main objective of our studyis to develop a new approach to the annealed proton exchange (APE) method for the fabrication of the multifunctional integrated optical chip (MIOC) used in fiber-optic gyro systems and to eliminate the loss of time and material, especially in mass production applications. In this work, self-polarized waveguides, which are the basic components of a MIOC device, were produced by the APE method and studied. With the developed method, controlled annealing trials have been carried out from a certain region on the LiNbO3 substrate used in waveguide production, and the annealing time specific to the annealing process was determined. By utilizing a special setup for the hot acid process, the proton exchange process was accomplished without a sudden temperature change of the substrate. Using prism coupling measurements of the fabricated waveguides, annealing times were determined to obtain index change values suitable for 45%–50% optical throughput. Mode profiles of devices with high optical throughput that were produced by the proposed method were measured, and it was seen that devices from different proton exchange runs had similar profiles. As a result, many undamaged substrates were fabricated, and their optical quality was found to be within the expected values.