Department of Physics

Many-body effects in a two-component, one-dimensional electron gas with repulsive, short-range interactions

Tanatar, B. (Elsevier, 1998-03-09)

We investigate the correlation effects in a two-component, one-dimensional electron gas interacting via repulsive δ function interactions. Electron correlations are treated within the approximation scheme of Singwi, Tosi, ...

Enhanced transmission of electromagnetic waves through split-ring resonator-shaped apertures

Sahin, L.; Aydin, K.; Sayan, G. T.; Ozbay, E. (Society of Photo-Optical Instrumentation Engineers (SPIE), 2011-06-21)

The design of aperture shape is a promising approach for enhanced transmission through a subwavelength aperture. We designed split-ring-resonator (SRR)-shaped apertures in order to increase the transmission through ...

InSb high-speed photodetectors grown on GaAs substrate

Kimukin, I.; Biyikli, N.; Ozbay, E. (American Institute of Physics, 2003)

We report InSb-based high-speed photodetectors grown on GaAs substrate. The p-i-n type photodetectors can operate at room temperature. Room-temperature dark current was 4 mA at 1 V reverse bias, and the differential ...

Design and Optimization of High-Speed Resonant Cavity Enhanced Schottky Photodiodes

Gokkavas, M.; Onat, B. M.; Ozbay, E.; Ata, E. P.; J. Xu; Towe, E.; Unlu, M. S. (IEEE, 1999-02)

Resonant cavity enhanced (RCE) photodiodes (PD’s) are promising candidates for applications in optical communications and interconnects where high-speed high-efficiency photodetection is desirable. In RCE structures, ...

The effect of GaN thickness inserted between two AIN layers on the transport properties of a lattice matched AllnN/AIN/GaN/AIN/GaN double channel heterostructure

Tulek, R.; Arslan, E.; Bayrakli, A.; Turhan, S.; Gokden, S.; Duygulu, O.; Kaya, A.; Firat, T.; Teke, A.; Ozbay, E. (Elsevier, 2014-01-31)

One AlInN/AlN/GaN single channel heterostructure sample and four AlInN/AlN/GaN/AlN/GaN double channel heterostructure samples with different values of the second GaN layer were studied. The interface profiles, crystalline ...

Optically Implemented Broadband Blueshift Switch in the Terahertz Regime

Shen, N H.; Massaouti, M.; Gokkavas, M.; Manceau, J M.; Ozbay, E.; Kafesaki, M.; Koschny, T.; Tzortzakis, S.; Soukoulis, C. M. (American Physical Society, 2011)

We experimentally demonstrate, for the first time, an optically implemented blueshift tunable metamaterial in the terahertz (THz) regime. The design implies two potential resonance states, and the photoconductive semiconductor ...

Resonant cavity enhanced detectors embedded in photonic crystals

Temelkuran, B.; Ozbay, E.; Kavanaugh, J. P.; Tuttle, G.; Ho, K. M. (American Institute of Physics, 1998)

We report a resonant cavity enhanced (RCE) detector built around a three-dimensional photonic band gap crystal. The RCE detector was built by placing a monopole antenna within the localized modes of planar and boxlike ...

Defect structures in metallic photonic crystals

Ozbay, E.; Temelkuran, B.; Sigalas, M. M.; Tuttle, G.; Soukoulis, C. M. (American Institute of Physics, 1996-12-16)

We have investigated metallic photonic crystals built around a layer‐by‐layer geometry. Two different crystal structures (face‐centered‐tetragonal and tetragonal) were built and their properties were compared. We obtained ...

Temperature dependent hot electron transport in slightly lattice mismatched AllnN/AIN/GaN heterostructures

Ilgaz, A.; Gokden, S.; Turk, R.; Teke, A.; Ozcelik, S.; Ozbay, E. (Institutul National de Cercetare-Dezvoltare pentru Optoelectronica,National Institute of Research and Development for Optoelectronics, 2014-10)

In this work, the hot-electron transport properties of AlInN/AlN/GaN HEMT structures with a high sheet electron density of 4.84x10(13) cm(-2) grown by MOCVD (Metal Organic Chemical Vapor Deposition) on sapphire substrate ...

Multi-gap individual and coupled split-ring resonator structures

Penciu, R. S.; Aydin, K.; Kafesaki, M.; Koschny, Th.; Ozbay, E.; Economou, N.; Soukoulis, C. M. (Optical Society of America, 2008)

We present a systematic numerical study, validated by accompanied experimental data, of individual and coupled split ring resonators (SRRs) of a single rectangular ring with one, two and four gaps. We discuss the behavior ...

Spoof-plasmon relevant one-way collimation and multiplexing at beaming from a slit in metallic grating

Cakmakyapan, S.; Serebrynanikov, A. E; Caglayan, H.; Ozbay, E. (Optical Society of America, 2012)

Diode and collimator/multiplexer functions are suggested to be combined in one device that is based on a thin metallic grating with a single subwavelength slit. A proper choice of the structural (a) symmetry of the grating ...

Compact wavelength de-multiplexer design using slow light regime of photonic crystal waveguides

Akosman, A. E.; Mutlu, M.; Kurt, H.; Ozbay, E. (Optical Society of America, 2011-11-21)

We demonstrate the operation of a compact wavelength de-multiplexer using cascaded single-mode photonic crystal waveguides utilizing the slow light regime. By altering the dielectric filling factors of each waveguide ...

Solar-blind AlGaN-based p-I-n photodetectors with high breakdown voltage and detectivity

Tut, T.; Yelboga, T.; Ulker, E.; Ozbay, E. (American Institute of Physics, 2008)

We report on the high performance solar-blind AlGaN-based p-i-n photodetectors that are grown by metal-organic chemical vapor deposition on c-plane sapphire substrates. The dark current of the 200 mu m diameter devices was ...

Electron transport properties in Al0.25Ga0.75N/AIN/GaN hetrostructures with different InGaN back barrier layers and GaN channel thickness grown by MOCVD

Kelekci, O.; Tasli, P. T.; Yu, H.; Kasap, M.; Ozcelik, S.; Ozbay, E. (Wiley-VCH Verlag, 2012)

The electron transport properties in Al0.25Ga0.75N/AlN/GaN/InxGa1-xN/GaN double heterostructures with various indium compositions and GaN channel thicknesses were investigated. Samples were grown on c-plane sapphire ...