Browsing by Author "Balcı, Osman"

Now showing items 1-10 of 10

    • Controlling electromagnetic waves with active graphene devices 

      Balcı, Osman (Bilkent University, 2015)

    • Controlling phase of microwaves with active graphene surfaces 

      Balcı, Osman; Kakenov, Nurbek; Kocabaş, Coşkun (American Institute of Physics Inc., 2017)
      In this letter, we report a method to control the reflection phase of microwaves using electrically tunable graphene devices. The device consists of mutually gated large-area graphene layers placed at a quarter-wave distance ...

    • Electrically controlled terahertz spatial light modulators with graphene arrays 

      Kakenov, Nurbek; Takan, T.; Özkan, V. A.; Balcı, Osman; Polat, Emre Ozan; Altan, H.; Kocabaş, Coşkun (IEEE, 2016)
      Gate-tunable high-mobility electrons on atomically thin graphene layers provide a unique opportunity to control electromagnetic waves in a very broad spectrum. In this paper, we describe an electrically-controlled multipixel ...

    • Electrically switchable metadevices via graphene 

      Balcı, Osman; Kakenov, Nurbek; Karademir, E.; Balcı, S.; Çakmakyapan, S.; Polat, E. O.; Cağlayan, H.; Özbay, Ekmel; Kocabaş, Coşkun (American Association for the Advancement of Science, 2018)
      Metamaterials 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 ...

    • Femtosecond pulse generation from an extended cavity Cr4+: Forsterite laser using graphene on YAG 

      Baylam I.; Ozharar, S.; Natali Cizmeciyan, M.; Balcı, Osman; Pince, Erçağ; Kocabaş, Coşkun; Sennaroglu, A. (Optical Society of America, 2013)
      A room temperature, multipass-cavity, femtosecond Cr4+:forsterite laser was modelocked with a single-layer graphene saturable absorber on a YAG substrate. The resonator produced nearly transform-limited 92 fs pulses near ...

    • Graphene nanoreactors : photoreduction of prussian blue in aqueous solution 

      Nappini, Silvia; Matruglio, Alessia; Naumenko, Denys; Dal Zilio, Simone; Lazzarino, Marco; De Groot, Frank M.F.; Kocabaş, Coşkun; Balcı, Osman; Magnano, Elena (American Chemical Society, 2017)
      Prussian dyes are characterized by interesting photomagnetic properties due to the photoinduced electron transfer involved in the Fe oxidation and spin state changes. Ferromagnetic Prussian blue (PB) in contact with titanium ...

    • Graphene-gold supercapacitor as a voltage-controlled saturable absorber for femtosecond pulse generation 

      Baylam, I.; Balcı, Osman; Kakenov, Nurbek; Kocabaş, Coşkun; Sennaroğlu, A. (OSA, 2015)
      We report, for the first time to our knowledge, a voltage-controlled graphene-gold supercapacitor saturable absorber, as a modulator with adjustable insertion loss for low-gain mode-locked lasers. Nearly transform-limited, ...

    • High frequency performance of individual and arrays of single-walled carbon nanotubes 

      Balcı, Osman; Kocabaş, Coşkun (Institute of Physics Publishing, 2012-05-28)
      We have studied the high frequency performance limits of single-walled carbon nanotube (SWNT) transistors in the diffusive transport regime limited by the acoustic phonon scattering. The relativistic band structure of ...

    • Hybrid J-Aggregate–graphene phototransistor 

      Balcı, Osman; Uzlu, Burkay; Yakar, Ozan; Polat, Nahit; Ari, O.; Tunç, İlknur; Kocabaş, Coşkun; Balcı, Sinan (American Chemical Society, 2020)
      J-aggregates are fantastic self-assembled chromophores with a very narrow and extremely sharp absorbance band in the visible and near-infrared spectrum, and hence they have found many exciting applications in nonlinear ...

    • Synthesis of graphene on ultra-smooth copper foils for large area flexible electronics 

      Polat, E. O.; Balcı, Osman; Kakenov, Nurbek; Kocabaş, Coşkun; Dahiya, R. (IEEE, 2015)
      This work demonstrates the synthesis of high quality, single layer graphene on commercially available ultra-smooth copper foils. The presented method will result in improved scalability of graphene based electronic and ...