Browsing by Author "Güven, Kaan"
Now showing items 112 of 12

Bandgap renormalization in quantum wires
Güven, Kaan; Bennett, C.R.; Tanatar, Bilal (TÜBİTAK, 1999)Improved techniques in semiconductor fabrication increased the interest in quantum wire structures, because of their optoelectronic device application possibilities. Manybody interactions among the electrons and holes ... 
Experimental analysis of true lefthanded behaviour and transmission properties of composite metamaterials
Güven, Kaan; Aydın, Koray; Özbay, Ekmel (Elsevier, 200512)We report the true lefthanded transmission of a composite metamaterial (CMM) consisting of periodically stacked splitring resonator (SRR) and wire elements. The negative permeability (μ < 0) gap is demonstrated explicitly ... 
Experimental observation of true lefthanded metamaterial
Aydın, Koray; Güven, Kaan; Özbay, Ekmel (IEEE, 2005)We report a true lefthanded (LH) behavior in composite metamaterials. The magnetic resonance of the SRR structure is demonstrated. Plasma frequency of the LH material is shown to be lower than that of the wires. 
Manybody interaction effects in quasionedimensional photoexcited electronhole systems
Güven, Kaan (Bilkent University, 1999)The work in this thesis concerns rnanybody interaction effects in a quasionedimensional electronhole plasma, which may be generated under intense photoexcitation in a semiconductor quantumwell wire. In particular, ... 
Nearfield measurement of a planar metasurface illuminated by dipole antennas
Saenz, E.; Güven, Kaan; Ederra, I.; Özbay, Ekmel; De Maagt, P.; Gonzalo, R. (IEEE, 200803)In this paper, the uniform illumination of a metasurface that is fed by a single dipole antenna or an array is experimentally investigated by means of nearfield measurements. The results of the scanned field, when the ... 
Negative refraction and subwavelength focusing using photonic crystals
Özbay, Ekmel; Aydın, Koray; Alıcı, Kamil Boratay; Güven, Kaan (SPIE, 200501)We review certain novel optical properties of twodimensional dielectric photonic crystals (PCs) which exhibit negative refraction behavior. We investigate two mechanisms which utilize the band structure of the PC and lead ... 
Phonon renormalization effects in low dimensional electronhole systems
Güven, Kaan (Bilkent University, 1995)Ia)vv (linuMisioiial sciniromluclor st i iid iii4's lia\4‘ 1и‘(М1 an (‘Xt(Misiv(‘ i4\soa,rrh iwcix ill (4)iul(4iscd iiiatlcr physics. In j^aii iculai', iiindi (‘llorl has 1)(Ч'п dcvolnd to lhc‘ study ol ciuasionediiiK'iisional ... 
Physics and applications of defect structures in photonic crystals
Özbay, Ekmel; Güven, Kaan; Bayındır, Mehmet (SPIE, 2003)Photonic crystals are three dimensional periodic structures having the property of reflecting the electromagnetic (EM) waves in all dimensions, for a certain range of frequencies. Defects or cavities around the same geometry ... 
Physics and applications of photonic nanocrystals
Özbay, Ekmel; Güven, Kaan; Aydın, Koray; Bayındır, Mehmet (Inderscience Publishers, 2004)Photonic nanocrystals are periodic dielectric or metallic structures having photonic bands in analogy to electronic bands of semiconductors. The presence of photonic bandgaps, where the propagation of photons of certain ... 
PlasmonLOphonon coupling effects on the drag rate in double quantumwell systems
Güven, Kaan; Tanatar, Bilal (Elsevier, 1997)We study the Coulomb drag rate for electrons in a doublequantumwell structure taking into account the electronoptical phonon interactions. The full wave vector and frequency dependent randomphase approximation (RPA) ... 
Spectral negative refraction and focusing analysis of a twodimensional lefthanded photonic crystal lens
Güven, Kaan; Aydın, Koray; Alıcı, Kamil Boratay; Soukoulis, C. M.; Özbay, Ekmel (American Physical Society, 200411)We report the spectral refraction analysis and focusing properties of a twodimensional, dielectric photonic crystal (PC) slab in freespace. A transverse electric polarized upper band of the crystal is used. The measured ... 
Twodimensional lefthanded metamaterial with a negative refractive index
Aydın, Koray; Güven, Kaan; Özbay, Ekmel (IOP, 2006)We present a twodimensional metamaterial with lefthanded properties in a certain frequency range where both effective dielectric permittivity and magnetic permeability is simultaneously negative. A wedgeshaped metamaterial ...