Browsing by Author "Hayber, Şekip Esat"

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Design and simulation of a novel fungus-shaped center embossed diaphragm for fiber optic pressure sensors
(Elsevier Science, 2021-01) Hayber, Şekip Esat; Aydemir, Umut; AYDEMİR, UMUT; 0000-0001-5396-4610; IXW-8105-2023
A novel structure with a fungus-shaped center embossed diaphragm (FCED) geometry has been proposed to modify in diaphragm-based Fabry-Perot fiber optic pressure sensors (FP-FOPS). The proposed FCED geometry was obtained by adding a pillar between the mesa and diaphragm. Before the simulation analysis of FCED, we derived mathematical equations of attenuation factor widening the acceptance radius. The attenuation factor is defined to understand sensor loss, which is neglected in the literature. With this derived formula, the light reflected from the deflected diaphragm and the light unguided in the fiber was detected. Since the deformation angle is zeroized in the FCED structures, the sensor loss due to the attenuation factor is eliminated. All the incident light being re-guided in the fiber. With FCED design's help, the decreasing sensitivity in the center embossed diaphragms (CED) has been prevented. Moreover, the deviation of the frequency response of FCED remains lower than 1% compared with the results of conventional diaphragms. As a result, it produces a more stable sensor, and the FCED structure is less affected by manufacturing errors. The researchers can benefit from the use of our presented results when designing and producing new diaphragm-based FP-FOPS.
The effect of mesa dimensions on mems diaphragms for fabry-perot interferometerbased fiber optic sensors
(Bursa Uludağ Üniversitesi, 2023-02-13) Atıf 4.0 Uluslararası; Durmaz, Ahmet; Hayber, Şekip Esat; Aydemir, Umut; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/Elektrik-Elektronik Mühendisliği.; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/Optik ve Fotonik Mühendisliği.; 0000-0002-8928-2563; 0000-0003-0062-3817; 0000-0001-5396-4610
In this study, the effects of mesa dimensions on sensor response in diaphragm-based FabryPerot fiber optic sensors (FOSs) were investigated in detail. Mesa diaphragms, also called centerembossed diaphragms, have been discussed sufficiently in the literature, but the effect of mesa thickness on sensor performance has not been discussed in detail. Moreover, there is no precise analytical solution for such diaphragms. For this reason, diaphragms with different thicknesses and radii were selected, and the deflection and frequency responses of the diaphragm according to the applied acoustic pressure were analyzed using the ANSYS software, depending on whether the mesa is thinner or thicker than the diaphragm. If the thickness of the mesa is smaller than the thickness of the diaphragm, the center deflection changes drastically. However, if the thickness of the mesa is two times greater than the thickness of the diaphragm, there is no significant change in the deflection results. Similarly, if the mesa thickness is thinner than the diaphragm, the sensor’s frequency response changes drastically with increasing mesa radius. In cases where the mesa thickness is larger than the diaphragm thickness, the frequency response changes less. According to the results, mesa dimensions should be considered when designing a mesa diaphragm-based Fabry-Perot FOS.
The experimental validation of designed fiber optic pressure sensors with epdm diaphragm
(IEEE-Inst Electrical Electronics Engineers Inc, 2019-03-26) Hayber, Şekip Esat; Tabaru, Timucin Emre; Saraçoğlu, Ömer Galip; Aydemir, Umut; Uludağ Üniversitesi/Mühendislik Fakültesi/Elektrik-Elektronik Mühendisliği Bölümü.; 0000-0001-5396-4610; V-2845-2018; 57198197314
This paper focused on the experimental validation of diaphragm-based Fabry-Perot fiber optic pressure sensors (D-FP-FOPS) with ethylene propylene diene terpolymers (EPDM) diaphragm as designed and analyzed sensor tip theoretically. We also used self-adhesive EPDM rubber as a diaphragm for the first time in the literature. Analytical calculation and finite element method (FEM) analysis were carried out to obtain values of fundamental resonance frequency (f(0)) and deflection (d) with diaphragm specific values of Young's modulus and Poisson's ratio measured by tensile tests. We produced D-FP-FOPS tip with EPDM diaphragm and obtained experimental f(0) between 250-400 Hz from extended signal to noise ratio (SNR) plot which figured out with the help of theoretical values of f(0). We also analyzed minimum detectable pressure (MDP) mapping which is used to confirm SNR mapping for D-FP-FOPS. We noticed that our sensor could be operated up to 1.6 Pa pressure which confirms the mechanical limit given in the literature. Before production of D-FP-FOPS, a pioneering way which includes design, analytical calculation, FEM analysis, and experimental validation was demonstrated as a novel. Moreover, since we used self-adhesive EPDM tape as a diaphragm material, our sensor tip cost is less than 50 $ which capable to compete with commercial sensors.
Optik haberleşme için lazer sinyali tabanlı düşük maliyetli devre tasarımı uygulaması
(Bursa Uludağ Üniversitesi, 2024-08-13) Çavuş, Berkay; Hayber, Şekip Esat; Bursa Uludağ Üniversitesi / Fen Bilimleri Enstitüsü / Elektronik Mühendisliği Anabilim Dalı; 0009-0007-1184-8807
Bu tez çalışmasında, çığ fotodiyotları (APD) ve transimpedans amplifikatörleri (TIA) optik kablosuz haberleşme ve algılama sistemleri için kullanılarak düşük maliyetli, yüksek performanslı ve düşük gürültülü bir devre tasarımı gerçekleştirilmiştir. Tasarım süreci, teorik temellerin belirlenmesi, simülasyon modelleme ve analizler, donanım testleri ile performans değerlendirmelerini kapsamaktadır. APD’ler, yüksek hassasiyet ve hızlı tepki süreleri sunan yarı iletken cihazlardır. Bu tezde, Excelitas C30737 serisi APD kullanılarak 500-1000 nm dalga boyu aralığında yüksek duyarlılık sağlanmıştır. APD’lerin çıkış sinyalleri, TIA devresi ile işlenmiş, sinyallerin kazancı artırılarak işleme ve ölçüme uygun hale getirilmiştir. Devre tasarımı, Altium Designer yazılımı kullanılarak gerçekleştirilmiştir. TIA, ters besleme devresi, kazanç devresi, güç devresi, besleme okuma ve sürme devreleri, lazer diyot sürücü devresi ve mikrodenetleyici devreleri bu yazılım ile optimize edilmiştir. Tasarım sürecinde LTSpice simülasyonları kullanılarak devrelerin doğruluğu ve performansı test edilmiştir. Laboratuvar test prosedürleri ile donanımın performansı ve güvenilirliği değerlendirilmiştir. Bu süreçte osiloskop, multimetre, güç kaynağı, sinyal jeneratörü ve spektrum analizörü gibi cihazlar kullanılarak testler gerçekleştirilmiştir. Test sonuçları, sinyal güçleri, gürültü seviyeleri, kazanç ve bant genişliği gibi kritik performans parametrelerini içermektedir. Sonuç olarak, tasarlanan TIA devresi yüksek kazanç, geniş bant genişliği ve iyi lineerlik sunarak optik kablosuz haberleşme ve algılama sistemlerinde güvenilir ve hassas ölçümler yapılmasına olanak sağlamaktadır. Tezde geliştirilen devrelerin performans analizi, optik iletişim teknolojilerinin gelecekteki gelişimine önemli katkılar sağlamaktadır.