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Publication Metadata only 16.4: the optics of an autostereoscopic multiview display(SID, 2010) Baghsiahi, Hadi; Selviah, David R.; Willman, Eero; Fernández, Anibal; Day, Sally E.; Surman, Phil A.; N/A; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Erden, Erdem; Chellappan, Kishore Velichappattu; Ürey, Hakan; Master Student; Researcher; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; N/A; 8579An autostereoscopic head-tracked back projection display that uses an RGB laser illumination source and a fast light engine is described. Images are horizontally scanned columns controlled by a spatial light modulator that directs two or more images in the directions of the apposite viewers 'eyes.Publication Metadata only 2D scanning MEMS stage integrated with microlens arrays for high-resolution beam steering(IEEE, 2009) Department of Electrical and Electronics Engineering; N/A; Department of Electrical and Electronics Engineering; N/A; N/A; N/A; Ürey, Hakan; Gökçe, Sertan Kutal; Holmstrom, Sven; Arslan, Aslıhan; Ataman, Çağlar; Seren, Hüseyin Rahmi; Faculty Member; Master Student; Researcher; Master Student; PhD Student; Master Student; Other; Department of Electrical and Electronics Engineering; College of Engineering; Graduate School of Sciences and Engineering; College of Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; N/A; 8579; N/A; N/A; N/A; N/A; N/A; N/AA novel MEMS stage using one set of comb fingers, capable of 2-axis motion is designed and developed. With an integrated 1.1mm square microlens-array it deflects 40um in-plane at 60V and 95um out-of-plane at 100V.Publication Metadata only 300 GHz broadband transceiver design for low-THz band wireless communications in indoor internet of things(Ieee, 2017) N/A; Department of Electrical and Electronics Engineering; N/A; Department of Electrical and Electronics Engineering; Khalid, Nabil; Abbasi, Naveed Ahmed; Akan, Özgür Barış; Researcher; PhD Student; Faculty Member; Department of Electrical and Electronics Engineering; College of Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; 6647This paper presents the architectural design of a 300 GHz transceiver system that can be used to explore the high speed communication opportunities offered by the Terahertz (THz) band for advanced applications of Internet-of-Things (IoT). We use low cost industry ready components to prepare a fully customizable THz band communication system that provides a bandwidth of 20 GHz that is easily extendable up to 40 GHz. Component parameters arc carefully observed and used in simulations to predict the system performance while the compatibility of different components is ensured to produce a reliable design. Our results show that the receiver provides a conversion gain of 51 dB with a noise figure (NE) of 9.56 dB to achieve a data rate of 90.31 Gbps at an operation range of 2 meters, which is suitable for high speed indoor IoT nodes. The flexible design of the transceiver provides groundwork for further research efforts in 5G IoT applications and pushing boundaries of throughputs to the order of terabits per second (Tbps).Publication Metadata only 3D coffee stains(Royal Soc Chemistry, 2017) N/A; N/A; Department of Electrical and Electronics Engineering; N/A; N/A; N/A; Department of Molecular Biology and Genetics; Department of Chemistry; Department of Chemistry; Department of Electrical and Electronics Engineering; Doğru-Yüksel, Itır Bakış; Söz, Çağla Koşak; Press, Daniel Aaron; Melikov, Rustamzhon; Begar, Efe; Çonkar, Deniz; Karalar, Elif Nur Fırat; Yılgör, Emel; Yılgör, İskender; Nizamoğlu, Sedat; PhD Student; PhD Student; Researcher; PhD Student; PhD Student; PhD Student; PhD Student; Faculty Member; Researcher; Faculty Member; Faculty Member; Department of Molecular Biology and Genetics; Department of Chemistry; Department of Electrical and Electronics Engineering; N/A; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); N/A; N/A; N/A; N/A; N/A; N/A; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Sciences; College of Sciences; College of Sciences; College of Engineering; N/A; N/A; N/A; N/A; N/A; N/A; 206349; N/A; 24181; 130295When a liquid droplet (e.g., coffee, wine, etc.) is splattered on a surface, the droplet dries in a ring-shaped stain. This widely observed pattern in everyday life occurs due to the phenomenon known as a coffee stain (or coffee ring) effect. While the droplet dries, the capillary flow moves and deposits the particles toward the pinned edges, which shows a 2D ring-like structure. Here we demonstrate the transition from a 2D to a 3D coffee stain that has a well-defined and hollow sphere-like structure, when the substrate surface is switched from hydrophilic to superhydrophobic. The 3D stain formation starts with the evaporation of the pinned aqueous colloidal droplet placed on a superhydrophobic surface that facilitates the particle flow towards the liquid-air interface. This leads to spherical skin formation and a cavity in the droplet. Afterwards the water loss in the cavity due to pervaporation leads to bubble nucleation and growth, until complete evaporation of the solvent. In addition to the superhydrophobicity of the surface, the concentration of the solution also has a significant effect on 3D coffee stain formation. Advantageously, 3D coffee stain formation in a pendant droplet configuration enables the construction of all-protein lasers by integrating silk fibroin with fluorescent proteins. No tools, components and/or human intervention are needed after the construction process is initiated; therefore, 3D coffee-stains hold promise for building self-assembled and functional 3D constructs and devices from colloidal solutions.Publication Metadata only 3D display dependent quality evaluation and rate allocation using scalable video coding(Ieee, 2009) N/A; N/A; Department of Electrical and Electronics Engineering; Saygılı, Görkem; Gürler, Cihat Göktuğ; Tekalp, Ahmet Murat; Master Student; PhD Student; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; 26207It is well known that the human visual system can perceive high frequency content in 3D, even if that information is present in only one of the views. Then, the best 3D perception quality may be achieved by allocating the rates of the reference (right) and auxiliary (left) views asymmetrically. However the question of whether the rate reduction for the auxiliary view should be achieved by spatial resolution reduction (coding a downsampled version of the video followed by upsampling after decoding) or quality (QP) reduction is an open issue. This paper shows that which approach should be preferred depends on the 3D display technology used at the receiver. Subjective tests indicate that users prefer lower quality (larger QP) coding of the auxiliary view over lower resolution coding if a "full spatial resolution" 3D display technology (such as polarized projection) is employed. On the other hand, users prefer lower resolution coding of the auxiliary view over lower quality coding if a "reduced spatial resolution" 3D display technology (such as parallax barrier - autostereoscopic) is used. Therefore, we conclude that for 3D IPTV services, while receiving full quality/resolution reference view, users should subscribe to differently scaled versions of the auxiliary view depending on their 3D display technology. We also propose an objective 3D video quality measure that takes the 3D display technology into account.Publication Metadata only 3D video tools(Springer Science and Business Media Deutschland GmbH, 2019) Dumic, Emil; Boussetta, Khaled; da Silva Cruz, Luis A.; Dagiuklas, Tasos; Liotta, Antonio; Politis, Ilias; Qiao, Yuansong; Torres Vega, Maria; Ye, Yuhang; Department of Electrical and Electronics Engineering; Tekalp, Ahmet Murat; Faculty Member; Department of Electrical and Electronics Engineering; College of Engineering; 26207This chapter presents an overview of different tools used in research and engineering of 3D video delivery systems. These include software tools for 3D video compression and streaming, 3D video players, and their interfaces. Other types of tools widely used in research studies and development of new networking solutions, such as network simulators, emulators, testbeds, and network analysis tools are also covered. In addition, several 3D video evaluation tools, which have been specifically designed for testing and evaluation of 3D video sequences subject to network impairments, are further described. The chapter also presents several examples of recent works that have been carried out based on one or more simulation, emulation, test, and/or evaluation tools in research studies or innovative solutions for relevant problems affecting 3D multimedia delivery.Publication Metadata only 3DTV and 3D video communications(Assoc Computing Machinery, 2010) Department of Electrical and Electronics Engineering; Tekalp, Ahmet Murat; Faculty Member; Department of Electrical and Electronics Engineering; College of Engineering; 26207With wider availability of low cost multi-view cameras, 3D displays, and broadband communication options, 3D media is destined to move from the movie theater to home and mobile platforms. In the near term, popular 3D media will most likely be in the form of stereoscopic video with associated spatial audio. Recent trials indicate that consumers are willing to watch stereoscopic 3D media on their TVs, laptops, and mobile phones. While it is possible to broadcast 3D stereoscopic media (two-views) over digital TV platforms today, streaming over IP will provide a more flexible approach for distribution of 3D media to users with different connection bandwidths and different 3D displays. In the intermediate term, free-view 3D video and 3DTV with multi-view capture are next steps in the evolution of 3D media technology. Recent free-view 3D auto-stereoscopic displays can display multi-view video, ranging from 5 to 200 views. Transmission of multi-view 3D media, via broadcast or on-demand, to end users with varying 3D display terminals and bandwidths is one of the biggest challenges to realize the vision of bringing 3D media experience to the home and mobile devices. This requires flexible rate-scalable, resolution-scalable, view-scalable, view-selective, and packet-loss resilient transport methods. In this talk, first I will briefly review the state of the art in 3D video formats, coding methods, IP streaming protocols and streaming architectures. We will then take a look at 3D video transport options. There are two main platforms for 3D broadcasting: standard digital television (DTV) platforms and the IP platform. I will summarize the approach of European project DIOMEDES which is developing novel methods for adaptive streaming of multi-view video over a combination of DVB and IP platforms. I will also summarize additional challenges associated with real-time interactive 3D video communications for applications such as 3D telepresence. Finally, open research challenges for the long term vision of haptic video and holographic 3D video will be presented.Publication Metadata only 48.4: Beam forming for a laser based auto-stereoscopic multi-viewer display(Blackwell Publishing Ltd, 2011) Baghsiahi, Hadi; Selviah, David R.; Willman, Eero; Fernández, Anibal; Day, Sally E.; Surman, Phil A.; N/A; Department of Electrical and Electronics Engineering; N/A; N/A; N/A; Department of Electrical and Electronics Engineering; Akşit, Kaan; Ölçer, Selim; Mostafazadeh, Aref; Erden, Erdem; Chellappan, Kishore Velichappattu; Ürey, Hakan; PhD Student; Other; N/A; Other; N/A; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; N/A; College of Engineering; N/A; N/A; N/A; N/A; N/A; 8579An auto-stereoscopic back projection display using a RGB multiemitter laser illumination source and micro-optics to provide a wider view is described. The laser optical properties and the speckle due to the optical system configuration and its diffusers are characterised. © 2011 SID.Publication Open Access A 2D MEMS stage for optical applications(Society of Photo-optical Instrumentation Engineers (SPIE), 2006) Ataman, Çağlar; Petremand, Yves; Noell, Wilfried; Epitaux, Marc; de Rooij, Nico F.; Department of Electrical and Electronics Engineering; Ürey, Hakan; Faculty Member; Department of Electrical and Electronics Engineering; College of Engineering; 8579A 2D MEMS platform for a microlens scanner application is reported. The platform is fabricated on an SOI wafer with 50/μm thick device layer. Entire device is defined with a single etching step on the same layer. Through four S-shaped beams, the device is capable of producing nonlinear 2D motion from linear ID translation of two pairs of comb actuator sets. The device has a clear aperture of 2mm by 2mm, which is hallowed from the backside for micro-optics assembly. In this paper, a numerical device model and its validation via experimental characterization results are presented. Integration of the micro-optical components with the stage is also discussed. Additionally, a new driving scheme to minimize the settling time of the device in DC operation is explored.Publication Metadata only A 35--μm pitch IR thermo-mechanical MEMS sensor with AC-coupled optical readout(IEEE-Inst Electrical Electronics Engineers Inc, 2015) Ferhanoğlu, Onur; Torun, Hamdi; N/A; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Adiyan, Ulaş; Çivitçi, Fehmi; Ürey, Hakan; PhD Student; Researcher; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Sciences; College of Engineering; N/A; 194282; 8579A thermo-mechanical MEMS detector with 35-mu m pixel pitch is designed, fabricated, and characterized. This fabricated design has one of the smallest pixel sizes among the IR thermo-mechanical MEMS sensors in the literature. The working principle of the MEMS detector is based on the bimaterial effect that creates a deflection when exposed to IR radiation in the 812-mu m waveband. The nanometer level out of plane mechanical motion is observed in response to IR heating of the pixel, which is detected by a diffraction grating-based optical readout. Performance of MEMS sensor arrays with optical readout have been limited by a large DC bias that accompanies a small AC signal. We developed a novel optical setup to reduce the DC term and the related noise using an AC-coupled detection scheme. Detailed noise characterization of the pixel and the readout system is reported in this paper. The noise equivalent temperature difference of our detector is measured as 216 mK using f/0.86 lens with the AC-coupled optical readout. Finally, we obtained a thermal image using a single MEMS pixel combined with a scanning configuration. Despite the reduced pixel size, the measured noise levels are comparable to the state-of-the-art thermo-mechanical IR sensors.