Photonics / Fotonik
Permanent URI for this collectionhttps://hdl.handle.net/11147/2590
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Article Citation - WoS: 9Citation - Scopus: 9Fourier Transform Plasmon Resonance Spectrometer Using Nanoslit-Nanowire Pair(American Institute of Physics, 2019) Uulu, Doolos Aibek; Ashirov, Timur; Polat, Nahit; Yakar, Ozan; Balcı, Sinan; Kocabaş, CoşkunIn this paper, we present a nanoscale Fourier transform spectrometer using a plasmonic interferometer consisting of a tilt subwavelength slit-nanowire pair on a metallic surface fabricated by the focused ion beam microfabrication technique. The incident broadband light strongly couples with the surface plasmons on the gold surface, and thus, surface plasmon polaritons (SPPs) are generated. The launched SPPs interfere with the incident light and generate high contrast interference fringes in the nanoslit. The transmitted SPPs through the metal nanoslit can decouple into free space and are collected by an objective in the far field. The spectroscopic information of the incidence light is obtained by fast Fourier transform of the fringe pattern of the SPPs. In our design, there is no need for a bulky dispersive spectrometer or dispersive optical elements. The dimension of the spectrometer is around 200 mu m length. Our design is based on inherent coherence of the SPP waves propagating through the subwavelength metal nanoslit structures etched into an opaque gold film.Article Citation - WoS: 18Citation - Scopus: 46Phosphor-Based White Led by Various Glassy Particles:control Over Luminous Efficiency(The Optical Society, 2019) Yüce, Hürriyet; Güner, Tuğrul; Balcı, Sinan; Demir, Mustafa MuammerGenerating white light through a mainstream remote phosphor design suffers from phosphor conversion efficiency loss due to a backscattering of light. Such a loss also reduces luminous efficiency of the resulting white light. To overcome this issue, various glassy scatterers with different morphologies such as glass bubbles, glass beads, and nanosized silica particles were employed as scatterers, together with a fixed amount of yellow phosphor (YAG:Ce3+) and a poly(dimethylsiloxane) (PDMS) matrix. In addition, the simulation of the system validates the rigorous multiple scattering of the incoming light most probably due to refractive index mismatch between the glass bubbles and surrounding PDMS matrix along with the internal reflections. (C) 2019 Optical Society of AmericaArticle Citation - WoS: 35Citation - Scopus: 36Colloidal Nanodisk Shaped Plexcitonic Nanoparticles With Large Rabi Splitting Energies(American Chemical Society, 2019) Mert Balcı, Fadime; Sarısözen, Sema; Polat, Nahit; Balcı, SinanWhen plasmons supported by metal nanoparticles interact strongly with molecular excitons or excitons of semiconducting quantum dots, plexcitons are formed in the strong coupling regime. The hybrid plexcitonic nanoparticles with a wide range of sizes and shapes have been synthesized by using wet chemistry methods or have been fabricated on solid substrates by using lithographic techniques. In order to deeply understand plasmon-exciton interaction at the nanoscale dimension and boost the performance of nanophotonic devices made of plexcitonic nanoparticles, new types of plexcitonic nanoparticles with tunable optical properties and outstanding stability at room temperature are urgently needed. Herein, we for the first time report pure colloidal nanodisk shaped plexcitonic nanoparticles with very large Rabi splitting energies, i.e., more than 350 meV. We synthesize silver nanoprisms by using seed mediated synthesis and then convert nanoprisms to nanodisks at a high temperature. Localized plasmon resonance of the silver nanodisk in the visible spectrum can be effectively tuned by heating. Subsequently, self-assembly of J-aggregate dyes on plasmonic nanodisks produces plexcitonic nanoparticles. We envision that colloidal nanodisk shaped plexcitonic nanoparticles with very large Rabi splitting energies and outstanding stability at room temperature will enlarge the application of plexcitonic nanoparticles in a variety of fields such as polariton laser, biosensor, plasmon molecular nanodevices, and energy flow at nanoscale dimensions.Conference Object Reversible Energy Transfer Between a Single Defect in Hbn and Graphene(OSA - The Optical Society, 2019) Özçeri, Elif; Arı, Ozan; Balcı, Sinan; Kocabaş, Coşkun; Ateş, SerkanWe present a reversible energy transfer between a single defect in hBN and graphene. Dynamic control of Fermi level of graphene results in switching on and off single photon emission from a single quantum emitter. © OSA 2019 © 2019 The Author(s)Article Citation - WoS: 370Citation - Scopus: 398Graphene-Based Adaptive Thermal Camouflage(American Chemical Society, 2018) Salihoğlu, Ömer; Uzlu, Hasan Burkay; Yakar, Ozan; Aas, Shahnaz; Balcı, Osman; Kakenov, Nurbek; Balcı, Sinan; Olçum, Selim; Süzer, Şefik; Kocabaş, CoşkunIn nature, adaptive coloration has been effectively utilized for concealment and signaling. Various biological mechanisms have evolved to tune the reflectivity for visible and ultraviolet light. These examples inspire many artificial systems for mimicking adaptive coloration to match the visual appearance to their surroundings. Thermal camouflage, however, has been an outstanding challenge which requires an ability to control the emitted thermal radiation from the surface. Here we report a new class of active thermal surfaces capable of efficient real-time electrical-control of thermal emission over the full infrared (IR) spectrum without changing the temperature of the surface. Our approach relies on electro-modulation of IR absorptivity and emissivity of multilayer graphene via reversible intercalation of nonvolatile ionic liquids. The demonstrated devices are light (30 g/m2), thin (<50 μm), and ultraflexible, which can conformably coat their environment. In addition, by combining active thermal surfaces with a feedback mechanism, we demonstrate realization of an adaptive thermal camouflage system which can reconfigure its thermal appearance and blend itself with the varying thermal background in a few seconds. Furthermore, we show that these devices can disguise hot objects as cold and cold ones as hot in a thermal imaging system. We anticipate that, the electrical control of thermal radiation would impact on a variety of new technologies ranging from adaptive IR optics to heat management for outer space applications.Article Citation - WoS: 11Citation - Scopus: 11Graphene-Quantum Dot Hybrid Optoelectronics at Visible Wavelengths(American Chemical Society, 2018) Salihoğlu, Ömer; Kakenov, Nurbek; Balcı, Osman; Balcı, Sinan; Kocabaş, ÇoşkunWith exceptional electronic and gate-tunable optical properties, graphene provides new possibilities for active nanophotonic devices. Requirements of very large carrier density modulation, however, limit the operation of graphene based optical devices in the visible spectrum. Here, we report a unique approach that avoids these limitations and implements graphene into optoelectronic devices working in the visible spectrum. The approach relies on controlling nonradiative energy transfer between colloidal quantum-dots and graphene through gate-voltage induced tuning of the charge density of graphene. We demonstrate a new class of large area optoelectronic devices including fluorescent display and voltage-controlled color-variable devices working in the visible spectrum. We anticipate that the presented technique could provide new practical routes for active control of light-matter interaction at the nanometer scale, which could find new implications ranging from display technologies to quantum optics.Article Citation - WoS: 134Citation - Scopus: 136Electrically Switchable Metadevices Via Graphene(American Association for the Advancement of Science, 2018) Balcı, Osman; Kakenov, Nurbek; Karademir, Ertuğrul; Balcı, Sinan; Çakmakyapan, Semih; Polat, Emre O.; Çağlayan, Hümeyra; Özbay, Ekmel; Kocabaş, ÇoşkunMetamaterials bring subwavelength resonating structures together to overcome the limitations of conventional materials. The realization of active metadevices has been an outstanding challenge that requires electrically reconfigurable components operating over a broad spectrum with a wide dynamic range. However, the existing capability of metamaterials is not sufficient to realize this goal. By integrating passive metamaterials with active graphene devices, we demonstrate a new class of electrically controlled active metadevices working in microwave frequencies. The fabricated active metadevices enable efficient control of both amplitude (>50 dB) and phase (>90°) of electromagnetic waves. In this hybrid system, graphene operates as a tunable Drude metal that controls the radiation of the passive metamaterials. Furthermore, by integrating individually addressable arrays of metadevices, we demonstrate a new class of spatially varying digital metasurfaces where the local dielectric constant can be reconfigured with applied bias voltages. In addition, we reconfigure resonance frequency of split-ring resonators without changing its amplitude by damping one of the two coupled metasurfaces via graphene. Our approach is general enough to implement various metamaterial systems that could yield new applications ranging from electrically switchable cloaking devices to adaptive camouflage systems.