Now showing items 1-10 of 10

    • Broadband THz modulators based on multilayer graphene on PVC 

      Kaya, E.; Kakenov, Nurbek; Kocabaş, Coşkun; Altan, H.; Esentürk, O. (IEEE, 2016)
      In this study we present the direct terahertz time-domain spectroscopic measurement of CVD-grown multilayer graphene (MLG) on PVC substrate with an electrically tunable Fermi level. In a configuration consisting MLG and ...
    • Compressive sensing imaging with a graphene modulator at THz frequency in transmission mode 

      Özkan, V. A.; Takan, T.; Kakenov, Nurbek; Kocabaş, Coşkun; Altan, H. (IEEE, 2016)
      In this study we demonstrate compressive sensing imaging with a unique graphene based optoelectronic device which allows us to modulate the THz field through an array of columns or rows distributed throughout its face.
    • Development of a rapid-scan fiber-integrated terahertz spectrometer 

      Keskin, H.; Altan, H.; Yavas, S.; Ilday, F. O.; Eken, K.; Sahin, A. B. (Springer New York LLC, 2014)
      Scientists in terahertz (THz) wave technologies have benefited from the recent developments in ultrafast laser technologies and RF technologies and applied these new gained techniques into characterizing a wide variety of ...
    • Focusing of THz waves with a microsize parabolic reflector made of graphene in the free space 

      Oguzer T.; Altintas, A.; Nosich A.I. (Springer International Publishing, 2017)
      Background: The scattering of H- and E-polarized plane waves by a two-dimensional (2-D) parabolic reflector made of graphene and placed in the free space is studied numerically. Methods: To obtain accurate results we use ...
    • Millimeter-wave scale metamaterials 

      Alıcı, Kamil Boratay; Özbay, Ekmel (IEEE, 2009-11)
      We review two metamaterial configurations, which are operating at the millimeter-wave scale, in terms of design, fabrication, and characterization. We observed both numerically and experimentally at around 100 GHz a narrow ...
    • Observation of gate-tunable coherent perfect absorption of terahertz radiation in graphene 

      Kakenov, N.; Balci, O.; Takan, T.; Ozkan, V. A.; Altan, H.; Kocabas, C. (American Chemical Society, 2016)
      We report experimental observation of electrically tunable coherent perfect absorption (CPA) of terahertz (THz) radiation in graphene. We develop a reflection-type tunable THz cavity formed by a large-area graphene layer, ...
    • On-chip characterization of THz Schottky diodes using non-contact probes 

      Khan, T. M.; Ghobadi, A.; Celik, O.; Caglayan, C.; Bıyıklı, Necmi; Okyay, Ali Kemal; Topalli, K.; Sertel, K. (IEEE Computer Society, 2016)
      We present non-contact characterization of GaAs Schottky contacts in the 140-220 GHz band. The non-contact probing technique utilizes planar on-chip antennas that are monolithically integrated with the coplanar waveguide ...
    • Repetition rate tuning of an ultrafast ytterbium doped fiber laser for terahertz time-domain spectroscopy 

      Keskin H.; Altan H.; Yavaş, Seydi; İlday, F. Ömer; Yagci, M.E.; Aydin O.; Eken, K.; Sahin, B. (IEEE, 2013)
      Repetition rate tuning enables the fast acquisition of THz pulse profiles [1]. By using this method we demonstrate a compact and broadband terahertz time domain spectroscopy system (THz TDS) driven by ytterbium doped fiber ...
    • Single and cascaded, magnetically controllable metasurfaces as terahertz filters 

      Serebryannikov, A. E.; Lakhtakia, A.; Özbay, Ekmel (Optical Society of America OSA, 2016)
      Transmission of a normally incident, linearly polarized, plane wave through either a single electrically thin metasurface comprising H-shaped subwavelength resonating elements made of magnetostatically controllable InAs ...
    • Single and coupled metasurfaces for tunable polarization-sensitive terahertz filters 

      Serebryannikov A.E.; Lakhtakia A.; Özbay, Ekmel (IEEE, 2016)
      We simulated the transmission of terahertz waves through a single metasurface and two coupled metasurfaces that comprise H-shaped subwavelength resonators made of InAs, a magnetically tunable material. The magnetostatic ...