Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/11
Browse
10 results
Search Results
Conference Object All-Optical Switching Based on Grating Written Photorefractive Slab/Fiber Waveguide Coupler(Institute of Electrical and Electronics Engineers Inc., 2002) Dinleyici, Mehmet SalihSince all optical switching is a key element for all kinds of optical networks, great amount of works have been dedicated either for material researches or various waveguide structures. Generally speaking the switching time of devices based on photorefractive effect are rather slow for today's high capacity optical fiber networks. In the field of waveguide architecture various geometries have been proposed and investigated for grating assisted or guided optical coupling for the purpose of designing all-optical switch, adddrop multiplexers, filters etc.Conference Object Citation - WoS: 3Citation - Scopus: 4Düşük Maliyetli Serbest-uzay Optik İletişim Sistemi Tasarımı(Institute of Electrical and Electronics Engineers Inc., 2004) Karatay, Okan; Dinleyici, Mehmet Salihhi recent years commercial and military interest in free-space optical communication (FSO) is growing due to the high bandwidths, portability and high security. Although the numerous advantages, atmospheric events such as attenuation and scintillation severely effects the link quality. Novel methods of mitigating atmospheric events were applied. Usage of large aperture lenses and high transmitted power according to decrease scintillation effects increases the system cost. Fresnel lenses, as an alternative to the classical optic system for mitigating scintillation effects would be a low-cost solution. As a result of the technological improvements on the output power and divergence angles of VSCEL (Vertical Cavity Surface Emitting Laser) enables high-speed cost effective FSO communication system design. In this research current applied FSO systems are analysed and fresnel lens optical system of alternative low-cost system designed.Conference Object Citation - Scopus: 13-D Switching Fabric Node Design(ACTA Press, 2004) Dinleyici, Mehmet Salih; Akın, OsmanIn this work we investigate an all-optical switching node that can be controlled by means of a transient grating, which is formed by interference of two Gaussian beams. This design considers 3-D architecture of switching fabrics.. real profile of Gaussian beams and fast switching time requirements. Four Wave Mixing (FWM) technique is applied in the evanescent field region of waveguide, showing chi((3)) nonlinearity. The formed grating is analysed by standart methods to obtain reflection coefficient and then coupling coefficient for power exchange between waveguides.Conference Object Citation - Scopus: 1Lcd Arkaışık Modüllerinde Moire Etkisinin İncelenmesi(Institute of Electrical and Electronics Engineers Inc., 2007) Dinleyici, Mehmet Salih; Akın, OsmanLCD panellerde, Sıvı Kristal (Liquid Crystal) camdan önce parlak ve homojen bir ışık dağılımı elde etmek için LCD Arkaışık Modülünün içinde Dağıtıcı tabaka, Dağıtıcı filmler ve Parlaklık Arttırıcı Film (Brightness Enhancement Film – BEF) kullanılır. Ancak modülün en üstünde kullanılan dağıtıcı film, ışığı dağıtmanın ve BEF’i korumanın yanında Moire Etkisini önlemek için de kullanılabilir. Bu çalışmada, bahsi geçen bu son dağıtıcı filmin Moire etkisinin yokedilmesi konusundaki rolü incelendi.Conference Object Tam Optik Anahtarlama için Faz Analizi(IEEE, 2006) Dinleyici, Mehmet Salih; Akın, OsmanIn this work we investigate an all-optical switching node that can be controlled by means of a transient grating, which is formed by interference of two Gaussian beams. This design considers phase effect in the reflection of light from transient grating, real profile of Gaussian beams and fast switching time requirements. Four Wave Mixing (FWM) technique is applied in the evanescent field region of waveguide, showing ?(3) nonlinearity. The formed grating is analysed by standart methods to obtain the phase of diffracted light and reflection coefficients to find the power exchange between reflection orders. © 2006 IEEE.Article A Novel All-Optical Routing Architecture for Optical Packet Switched Networks(Springer Verlag, 2006) Mocan, Bora; Dinleyici, Mehmet SalihIncreasing bandwidth demand, mostly driven by the Internet Protocol (IP), has made researchers consider to deploy all-optical devices into packet switched networks. Despite huge bandwidth of the optical communication links (optical fiber) the usable capacity is limited due to bottlenecks (congestions) at the switching nodes. In this paper, a novel all-optical routing architecture is proposed for optical packet switched networks. In the design, practical optical devices (gratings, threshold elements, optical delays, and couplers) have been improved and exploited in order to integrate into an all-optical routing device. The system has been implemented and simulated by using an photonics simulation package (VPI-Virtual Photonics). The packets conveying a three-bit routing information tag at the bit rate of 10 Gbps have been successfully routed between two links. Some of the components are standard tools of the simulation package and some needed to be designed using the transfer function or theory developed in the literature. Noise and losses associated to the nonideal nature of the components are considered in the simulation as well.Article Citation - WoS: 5Citation - Scopus: 7An Experimental Work on Optical Component Based on D-fiber/Slab Evanescent Coupling Structure(Springer Verlag, 2003) Dinleyici, Mehmet SalihFiber/slab coupler structure has been exploited as a passive in-line optical fiber component for functions of filtering, intensity modulating and switching by many researchers. In this work a device based on the elliptic core D-fiber and polymer slab waveguide is proposed and its fabrication is experimentally investigated. The device is constructed by placing the polymer slab on the top of the flat side of the D-fiber, and then they are tested for transmission characteristics and polarization preserving properties for various configurations. The geometrical uniformity of the device is examined under Scanning Electron Microscope for the purpose of device performance evaluation. Potential usage of this device as an all-optical switch is also discussed at the end.Article Citation - WoS: 1Citation - Scopus: 1Device length requirement in slab/fiber evanescent coupler(Taylor and Francis Ltd., 2000) Dinleyici, Mehmet SalihThe effective device lengths of the fiber half-coupler for various radii of curvatures was found. This calculated length was about a thousand times greater than that calculated by the model method. The device has enough effective interaction length. It also helps in finding the accuracy of estimations made by the CMT and modal method.Article Citation - WoS: 8Citation - Scopus: 9Calculation of the Wavelength Filter Properties of the Fiber-Slab Waveguide Structure Using Vector Mode Expansion(Institute of Electrical and Electronics Engineers Inc., 1998) Dinleyici, Mehmet Salih; Patterson, David B.A vectorial solution technique is applied to investigate the dispersion characteristics of the ridge modes of a waveguide structure comprising a slab and optical fiber. The power transmission characteristics of the device with respect to wavelength are calculated under various device parameters, such as slab index and fiber-slab separation. We discuss the effects of such parameters on the bandwidth and rejection of the notch filter produced by this structure.Article Citation - WoS: 19Citation - Scopus: 23Vector Modal Solution of Evanescent Coupler(Institute of Electrical and Electronics Engineers Inc., 1997) Dinleyici, Mehmet Salih; Patterson, David B.We present a vector modal solution for the evanescent coupler comprising an optical fiber and a slab waveguide. We identify the normal vector ridge modes of the device for different configurations. The dispersion characteristics and the power transmission properties of these modes are presented. Also, the effect of the proximity between the waveguides on the ridge modes is investigated.