题目：Coupling in detuned photonic molecules – mapping photonic crystals with light
报告人：Professor Robert Anthony Taylor（Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom）
摘要：
Photonic molecules and arrays of coupled cavities have recently found many applications in nanophotonics, including single photon emitters [1] and quantum information processing [2]. In general, the mode coupling found in these systems greatly enhances the effect that is sought-after, or conversely reduces the energy required to observe such an effect with respect to an isolated cavity. We present here a study of the effects of cavity detuning on the mode splitting of a photonic molecule consisting of two side-by-side coupled photonic crystal waveguide cavities. Results show a clear signature of a coupled system using microphotoluminescence microscopy at near telecom wavelengths. We are able to spatially map the profile of the antisymmetric (antibonding) and symmetric (bonding) modes of the coupled cavities (photonic molecules) in the presence of manufacturing imperfections. These results, supported by theory, show that the supermode with the lowest energy concentrates in the cavity with the largest effective volume resulting from lithographic imperfections. Modeling implies that the coupling is sensitive to nm displacements in the lattice defining the cavity. Such sensitivity could be used to define an all-optical switch using photonic crystal waveguides. In addition, simulations using imported SEM images of fabricated structures show that the coupling can be made significantly more robust by reducing the hole size defining the crystal. This also emphasizes that the device should be shielded from oxidation to preserve the coupling.
1. T. C. H. Liew and V. Savona, Phys. Rev. Lett. 104, 183601 (2010)
2. Y. Sato et al, Nature Photon. 6, 56 (2012)
简介：
Professor Robert Anthony Taylor received his PhD from the University of Oxford at September 1985. Since 1987, he has been working at Oxford, concentrating on the investigation of the time-resolved optical properties of semiconductors using ultrafast laser techniques. In 2008, he was awarded the title of Professor of Condensed Matter Physics, and in 2010 was pointed as the Associate Head of Mathematical, Physical and Life Science Division. His early work was dedicated to GaAs quantum wells. The recent work is focusing on III-V nitride semiconductors. His latest projects work on blue single photon sources and microcavity-coupled single quantum dots, and the coupling of excitons in long-wavelength InAs quantum dots to cavities and the control and emission of photons. He has published over 180 papers in journals and conference proceedings, and has been invited to give plenary speeches at conferences, and is a regular referee for the American Institute of Physics, the American Physical Society and the Institute of Physics.
时间：2013年9月27日（星期五）下午15：00
地点：中科院物理研究所M楼236会议室
联系人：许秀来 研究员 （Tel:82649820）
金奎娟 研究员（Tel：82648099）
主办单位：中国科学院光物理重点实验室
