Home Page Researchers Uriel Levy

Uriel Levy

School of Engineering and Computer Science
Faculty of Science
The Hebrew University, Jerusalem 91904, Israel
Tel: +972-2-6584256; Fax: +972-2-6584256
E-mail: ulevy@cc.huji.ac.il
Website: http://aph.huji.ac.il/people/Levy/index.htm


Nanophotonics and Optofluidics

In recent years, optical devices and systems are shrinking in size, with the ultimate goal of developing integrated on-chip photonic systems, similarly to VLSI electronic devices. Nanophotonics is expected to play a key role in future on-chip photonic devices and systems, being an enabling technology allowing the miniaturization and integration of optical components and devices. Our laboratory is focused on the design, fabrication and experimental characterization of various passive and active nanophotonics and nanoplasmonic devices for variety of applications including optical communication and signal processing, illumination, imaging, and optical storage. As dimensions are shrinking, the issue of self heating of devices is becoming a key issue, and heat removal solutions are needed. In our laboratories, we adopted a technique based on thermo couple probe in order to measure the self heating effect of nanophotonics resonant structures. From these measurements we can estimate the strength of the effect as well as the thermal distribution across the device. With the aid of such measurements it may be possible to design structures for better heat removal with the result of lower self heating and better stability during operation. Fig. 1 shows the thermal distribution across a micro ring resonator, where heat is generated due to free carriers? absorption.

Figure 1: Heat measurements in the near field. a) Thermal map of a doped resonator. b) Thermal map of an un doped resonator.

Another recent significant development is the demonstration of a plasmonic enhanced silicon Schottky detector. Using the plasmonic enhancement of the internal photoemission process we demonstrate the detection of sub-bandgap energy photons (in the ~1.5 microns regime) using silicon detector. This discovery may lead to the realization of low cost silicon detectors in the near IR regime, eliminating the need for expensive III/V solutions. We recently enhanced the responsivity of the Schottky detector by using the concept of roughness engineering (Fig. 2).

Figure 2: (Left) SEM micrograph of the integrated Schottky device. (Right) I-V curves at different optical powers.

 

Specific research topics related to Nanoscience and Nanotechnology:

  • Light-matter interactions at the nanoscale: Nanoscale confinement of light and its interaction with matter for detection, emission, and nonlinear interactions of light.
  • Silicon nanophotonics: The realization of nanoscale photonic devices in silicon.
  • Nanophotonics for polarization control:  Design of nanostructures for the control of polarization of light in space.
  • Nanomodulators: Optoelectronic devices on the nanoscale for light modulation and switching.
  • Silicon Plasmonics: Active silicon plasmonic components and devices

List of publications in Nanoscience and Nanotechnology (2011-2012)

  • A. Yanai and U. Levy, "Radiation of a uniformly moving line charge in a zero-index metamaterial and other periodic media," Opt. Express 20, 18515-18524 (2012).
  • Y. Sebbag, I. Goykhman, B. Desiatov, T. Nachmias, O. Yoshaei, M. Kabla, S. E. Meltzer, and U. Levy, ?Bistability in Silicon microring resonator based on strain induced by a piezoelectric PZT thin film,? Appl. Phys. Lett. 100, 141107 (2012).
  • L. Stern, I. Goykhman, B. Desiatov, and U. Levy, "Frequency Locked Micro Disk Resonator for real time and precise monitoring of refractive index," Opt. Lett. 37, 1313-1315 (2012).
  • C. L. C. Smith, B. Desiatov, I. Goykmann, I. Fern?ndez-Cuesta, U. Levy, and Anders Kristensen, ?Bragg grating filters in plasmonic V-groove waveguides via nanoimprint lithography, ? Opt. Express 20, 5696-5706 (2012).
  • B. Desiatov, I. Goykhman, and U. Levy, ?Parabolic tapered photonic crystal cavity in silicon,? Appl. Phys. Lett, 100, 041112 (2012).
  • A. Yanai, M. Orenstein, and U. Levy, ?Giant resonance absorption in ultra-thin metamaterial periodic structures,? Opt. Express 20, 3693-3702 (2012).

Three most significant publications in the last five years:

  • U. Levy, M. Abashin, K. Ikeda, A. Krishnamoorthy, J. Cunningham and Y. Fainman, "Inhomogeneous Dielectric Metamaterials with Space-Variant Polarizability," Phy. Rev. Lett, 98, 243901-243904 (2007).
  • I. Goykhman, B. Desiatov, J. Khurgin, J. Shappir, and U. Levy, "Locally Oxidized Silicon Surface-Plasmon Schottky Detector for Telecom Regime," Nano Lett. 11, (2011). (also highlighted in Nature Photonics)
  • G. M. Lerman, A. Yanai and U. Levy, "Demonstration of Nanofocusing by the use of Plasmonic Lens Illuminated with Radially Polarized Light,"  Nano Lett., 9, 2139-2143, (2009).

Patents (2007-2012)

  • On Chip Tunable Optical Devices Actuated by Electro-wetting on dielectric
  • Patent on Solar Cells
  • Patent on radial polarization interferomenter

Cooperation with industries and defense projects (2007-2012):

  • RAFAEL funded project on "Silicon nanophotonics",
  • MAFAT funded activity on radially polarized laser
  • MAFAT funded activity on nanometric lens
  • MAGNET - TERASANTA
  • KAMIN
  • SOREQ ? Funded activity on hollow waveguides

Distinctions and awards:

  • 2010 - Ben Porath Prize
  • 2008-2010 Peter Brojde scholar
  • 2007 - Golda Meir fellow

Students, postdocs and researchers:

Ph.D. students: Ilya Goykhman (jointly with Prof. J. Shappir), Boris Desiatov, Avner Yanai, Liron Stern, Meir Grajower
M.Sc students:  Mor Tsur, Yoel Sebag, Ronen Chriki (jointly with Prof. J. Shappir), Jonathan Bar David, Alex Neiman.

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