February 2010 Vol. 8 No. 2

View from the Top

• Yasuyoshi Katayama, Director and Executive Vice President, Director of Technology Planning Department, NTT

  

  Supporting Japan as
  an Issue-facing Developed Country
  through Coordination and Collaboration—
  New Service Creation by ICT

  Overview
  NTT Director and Executive Vice President Yasuyoshi Katayama oversees the entire network as director of NTT’s Technology Planning Department. We asked him about specific activities in the NTT Group—a driving force behind information and communications technology—to provide services for the Next Generation Network rollout period from the viewpoints of direction, international contributions, and social contributions.

Special Feature: Silicon Photonic Technologies Leading the Way to a New Generation of Telecommunications

• R&D Trends in Silicon Photonics

  

  Abstract
  Silicon photonics could, by integrating optical and electronic circuits on silicon, reduce the costs and power consumption of networks while meeting the need for advanced functionality. Further expansion of the information society will require optical networks with greater capacities and higher speeds and high-performance electronic circuits with faster operation. However, these developments will increase costs and power consumption. This article overviews research and development trends and introduces the other articles in this Special Feature.

• Polarization-independent Ultrasmall Silicon Photonic Circuits

  

  Abstract
  This article introduces polarization diversity technology that could solve the problem of polarization dependence in ultrasmall silicon photonic circuits, which is hindering their practical implementation. Polarization-manipulating devices fabricated using ultrafine nanoprocessing and thin-film-formation technologies should lead to inexpensive, low-power photonic devices for telecommunications use.

• Ultrasmall Silicon Photonic Devices and Integration Technology Toward Photonic-electronic Convergence

  

  Abstract
  This article introduces the current status of silicon photonic device integration technology using as an example the monolithic integration of a silicon-wire-waveguide variable optical attenuator and a germanium photodetector, which are devices that we have developed with photonic-electronic convergence in mind.

• Extremely-low-power-consumption Thermo-optic Switch with Silicon-silica Hybrid Structure

  

  Abstract
  In this article, we introduce an optical switch with extremely low power consumption that unites the silicon photonic and silica-based planar lightwave circuit technologies developed at NTT Photonics Laboratory.

• Silicon-based Large-scale Photonic Crystal Nanocavity Arrays for Slow-light Applications

  

  Abstract
  We have developed a periodic array of photonic crystal nanocavities that acts as a slow-light waveguide with acceptable values of bandwidth and group velocity dispersion. The ultrahigh quality factor of 106 allows the array to couple 300 nanocavities, which delay an optical pulse by over 150 ps, which is more than thirteen times the original pulse width.

• Entanglement Generation Using Silicon Wire Waveguide

  

  Abstract
  Generating high-purity entangled photon pairs is an important step toward quantum information processing using photons. In this article, we describe the world’s first ever experiment on generating entanglement using a spontaneous parametric process in a silicon wire waveguide.

Global Standardization Activities

• Standardization Activities in IEC/CISPR for Communications Electromagnetic Compatibility (EMC)

  

  Abstract
  This article reports on the latest standardization activities for electromagnetic compatibility (EMC) for communications and summarizes the Plenary Meeting of IEC/CISPR 2009 held in Lyon, France, from September 21 to October 1, 2009, and the discussions conducted there on subjects related to telecommunications. EMC is an important issue for the NTT Group, which defines NTT Technical Requirements (NTT-TRs) in order to provide safe and secure telecommunications services.

Papers Published in Technical Journals and Conferences

• Papers Published in Technical Journals and Conferences