Browsing by Author "İlday, Serim"

Now showing 1 - 8 of 8

Open Access
Breaking crosstalk limits to dynamic holography using orthogonality of high-dimensional random vectors
(Nature Publishing Group, 2019) Makey, Ghaith; Yavuz, Özgün; Kesim, Denizhan K.; Turnalı, Ahmet; Elahi, Parviz; İlday, Serim; Tokel, Onur; İlday, F. Ömer
Holography is the most promising route to true-to-life three-dimensional (3D) projections, but the incorporation of complex images with full depth control remains elusive. Digitally synthesized holograms1,2,3,4,5,6,7, which do not require real objects to create a hologram, offer the possibility of dynamic projection of 3D video8,9. Despite extensive efforts aimed at 3D holographic projection10,11,12,13,14,15,16,17, however, the available methods remain limited to creating images on a few planes10,11,12, over a narrow depth of field13,14 or with low resolution15,16,17. Truly 3D holography also requires full depth control and dynamic projection capabilities, which are hampered by high crosstalk9,18. The fundamental difficulty is in storing all the information necessary to depict a complex 3D image in the 2D form of a hologram without letting projections at different depths contaminate each other. Here, we solve this problem by pre-shaping the wavefronts to locally reduce Fresnel diffraction to Fourier holography, which allows the inclusion of random phase for each depth without altering the image projection at that particular depth, but eliminates crosstalk due to the near-orthogonality of large-dimensional random vectors. We demonstrate Fresnel holograms that form on-axis with full depth control without any crosstalk, producing large-volume, high-density, dynamic 3D projections with 1,000 image planes simultaneously, improving the state of the art12,17 for the number of simultaneously created planes by two orders of magnitude. Although our proof-of-principle experiments use spatial light modulators, our solution is applicable to all types of holographic media.
Open Access
Dynamic evolution of hyperuniformity in a driven dissipative colloidal system
(Institute of Physics Publishing Ltd., 2021-06-18) Nizam, Seleme Ümmü; Makey, Ghaith; Barbier, Michaël; Kahraman., S.S; Demir, Esin; Shafigh, Ehsan Eslami; Galioğlu, Sezin; Vahabli, D.; Hüsnügil, Sercan; Güneş, Muhammed H.; Yelesti, Efe; İlday, Serim
Hyperuniformity is evolving to become a unifying concept that can help classify and characterize equilibrium and nonequilibrium states of matter. Therefore, understanding the extent of hyperuniformity in dissipative systems is critical. Here, we study the dynamic evolution of hyperuniformity in a driven dissipative colloidal system. We experimentally show and numerically verify that the hyperuniformity of a colloidal crystal is robust against various lattice imperfections and environmental perturbations. This robustness even manifests during crystal disassembly as the system switches between strong (class I), logarithmic (class II), weak (class III), and non-hyperuniform states. To aid analyses, we developed a comprehensive computational toolbox, enabling real-time characterization of hyperuniformity in real- and reciprocal-spaces together with the evolution of several order metric features, and measurements showing the effect of external perturbations on the spatiotemporal distribution of the particles. Our findings provide a new framework to understand the basic principles that drive a dissipative system to a hyperuniform state.
Open Access
Laser writing of nanostructures deep inside Gallium Arsenide (GaAs)
(OSA, 2018) Tokel, Onur; Turnalı, Ahmet; Deminskyi, Petro; İlday, Serim; İlday, F. Ömer
Recently, we have showed a direct laser writing method that enables the first subsurface modifications and functional devices created deep inside silicon. Here, we extend the technique demonstrating the first controlled subsurface nanostructures in GaAs.
Open Access
Laser-patterning stainless steel with nonlinear laser lithography for enhanced tribological properties
(IEEE, 2015) Gnilitskyi, I.; Pavlov, Ihor; Rotundo, F.; Orazi, L.; İlday, Serim; Martini, C.; İlday, F. Ömer
The production of nanostructures on different materials attracts much attention in different fields of manufacturing as a result of increased availability, affordability and technical capability of laser-based methods [1,2]. However, some shortcomings such as relatively low speed of processing, problems with material control, and lack of uniformity and/or repeatability over large areas continue to limit their practical adaptation.
Open Access
Laser-slicing of silicon with 3D nonlinear laser lithography
(OSA, 2017) Tokel, Onur; Turnalı, Ahmet; Çolakoğlu, T.; İlday, Serim; Borra, M. Z.; Pavlov, Ihor; Bek, A.; Turan, R.; İlday, Fatih Ömer
Recently, we have showed a direct laser writing method that exploits nonlinear interactions to form subsurface modifications in silicon. Here, we use the technique to demonstrate laser-slicing of silicon and its applications.
Open Access
Rich complex behaviour of self-assembled nanoparticles far from equilibrium
(Nature Publishing Group, 2017) İlday, Serim; Makey, Ghaith; Akgüç, Gürsoy Bozkurt; Yavuz, Özgün; Tokel, Onur; Pavlovi, İhor; Gülseren, Oğuz; İlday, Faruk Ömer
A profoundly fundamental question at the interface between physics and biology remains open: what are the minimum requirements for emergence of complex behaviour from nonliving systems? Here, we address this question and report complex behaviour of tens to thousands of colloidal nanoparticles in a system designed to be as plain as possible: the system is driven far from equilibrium by ultrafast laser pulses that create spatiotemporal temperature gradients, inducing Marangoni flow that drags particles towards aggregation; strong Brownian motion, used as source of fluctuations, opposes aggregation. Nonlinear feedback mechanisms naturally arise between flow, aggregate and Brownian motion, allowing fast external control with minimal intervention. Consequently, complex behaviour, analogous to those seen in living organisms, emerges, whereby aggregates can self-sustain, self-regulate, self-replicate, self-heal and can be transferred from one location to another, all within seconds. Aggregates can comprise only one pattern or bifurcated patterns can coexist, compete, endure or perish.
Open Access
Self-dissimilarity, irreversibility and robustness in mode-locked fiber oscillators
(OSA, 2018) Makey, Ghaith; Teamir, Tesfay; İlday, Serim; İlday, F. Ömer
We introduce self-dissimilarity as measure of phase space complexity and predictor of robustness against perturbations. As nonlinearity increases, phase space becomes a random fractal, just before critical transitions. Measurements confirm powerlaw dependence over 7 decades.
Open Access
Universality of dissipative self-assembly from quantum dots to human cells
(Nature Research, 2020) Makey, Ghaith; Galioğlu, Sezin; Ghaffari, Roujin; Engin, E. D.; Yıldırım, Gökhan; Yavuz, Özgün; Bektaş, O.; Nizam, Ü. S.; Akbulut, Özge; Şahin, Özgür; Güngör, Kıvanç; Dede, Didem; Demir, Hilmi Volkan; İlday, Fatih Ömer; İlday, Serim
An important goal of self-assembly research is to develop a general methodology applicable to almost any material, from the smallest to the largest scales, whereby qualitatively identical results are obtained independently of initial conditions, size, shape and function of the constituents. Here, we introduce a dissipative self-assembly methodology demonstrated on a diverse spectrum of materials, from simple, passive, identical quantum dots (a few hundred atoms) that experience extreme Brownian motion, to complex, active, non-identical human cells (~1017 atoms) with sophisticated internal dynamics. Autocatalytic growth curves of the self-assembled aggregates are shown to scale identically, and interface fluctuations of growing aggregates obey the universal Tracy–Widom law. Example applications for nanoscience and biotechnology are further provided.