Speaker: Prof. Ali Serpengüzel, Koç University

Topic: "Silicon Microspheres and Meandering Waveguides for Fiber Optics and Integrated Photonics"

Location: Middle East Technical University, Ankara, Turkey

Abstract: Spherical optical microcavities [1] are building blocks of three dimensional photonics, as linear optical microcavities are building blocks of one dimensional photonics [2]. Dielectric and semiconductor [3] based lightwave circuit elements are integrated into fiber optics and integrated photonics. Specially, silicon microspheres lead themselves to various lightwave circuit element applications such as channel dropping filters [4] tunable filters, [5] and optical modulators [6] using optical fiber half couplers manufactured from single mode optical fibers. On the integrated optics side, silicon on oxide (SOI)-distributed feedback (DFB) meandering waveguides, as novel integrated optical elements, can exhibit a variety of spectral responses such as coupled resonator induced transparency filter, Fano resonator, hitless filter, Lorentzian filter, Rabi splitter, self coupled optical waveguide, and tunable power divider [7].  We focus on properties of silicon spherical resonators, and SOI-DFB meandering waveguides, and their potential for practical applications in fiber optics and integrated photonics.

[1] A. Serpengüzel, S. Arnold, and G. Griffel, "Excitation of Resonances of Microspheres on an Optical Fiber," Opt. Lett. 20, 654-656 (1995).
[2] A. Serpengüzel, A. Aydınlı, A. Bek, and M. Güre, "Visible photoluminescence from planar amorphous silicon nitride microcavities," J. Opt. Soc. Am. B 15, 2706-2711 (1998).
[3] N. M. Gasanly, A. Serpengüzel, O. Gürlü, A. Aydınlı, and I. Yılmaz, "Dependence of the photoluminescence of Tl2InGaS4 layered crystal on temperature and excitation intensity," Solid State Commun. 108, 525-530 (1998).
[4] Y.O. Yılmaz, A. Demir, A. Kurt, and A. Serpengüzel, "Optical Channel Dropping with a Silicon Microsphere," IEEE Photon. Technol. Lett. 17, 1662-1664 (2005).
[5] A. Serpengüzel, A. Kurt, and U.K. Ayaz, "Silicon microspheres for electronic and photonic integration," Photon. Nanostructur.: Fundam. Appl. 6, 179–182 (2008).
[6] E. Yüce, O. Gürlü, and A. Serpengüzel, "Optical Modulation with Silicon Microspheres," IEEE Photon. Technol. Lett. 21, 1481-1483 (2009).
[7] C. B. Dağ, M. A. Anıl, and A. Serpengüzel, "Meandering Waveguide Distributed Feedback Lightwave Circuits," J. Lightwave Technol, 33, 1691-1702 (2015).


Bio: Ali Serpengüzel received his Ph.D. in Applied Physics from Yale University. At Yale, he worked on stimulated Raman scattering from droplets and sprays. Later on, he joined Polytechnic University, Microparticle Photophysics Laboratory for postdoctoral work, where he performed the first coupling experiment of solid microspheres to optical fibers. Afterwards, he joined Bilkent University as a faculty member, where he concentrated his research on the optoelectronic properties of semiconductor microcavities. He is currently a Professor of Physics and the Director of the Koç University, Microphotonics Research Laboratory, Est. 2000. His current research focuses on integrated photonics with optical many novel microresonator and waveguide structures. Other research interests include optical spectroscopy in complex media, nanophotonics, nonlinear optics, and laser diagnostics. He is a fellow of SPIE, a senior member of IEEE and OSA, and a member of Sigma-Xi.

  Date and Time




  • Ankara, Ankara
  • Turkey


Prof. Ali Serpenguzel


Silicon Microspheres and Meandering Waveguides for Fiber Optics and Integrated Photonics