Tatsuo Kanetake

Quasi‐epitaxial growth of diacetylene films by vacuum deposition

The quasi‐epitaxial growth of vacuum‐deposited films of diacetylenes on various substrates, including uniaxially aligned polymer surfaces formed with rubbing treatment or Langmuir–Blodgett technique, is reported. The oriented polydiacetylene (PDA) films are readily obtained from these monomer films using photopolymerization. Highly oriented PDA films with excellent optical qualities have been obtained on rubbed polyethylene terephthalate surfaces. The typical dichroic ratio of these oriented PDA films is more than 100:1. This ratio is high enough to permit the application of these films to optical waveguide devices. The method for obtaining these highly oriented PDA films is described in detail. In addition, the structure, the morphology, and the optical anisotropy of these PDA films is examined by x‐ray and electron diffraction, electron microscopy, and other optical means.

Optical cross-connect systems for restoration of backbone fiber networks

Summary form only given. As the capacity of backbone networks is becoming larger, restoration against fiber/cable failures must become faster, because large amounts of data would be lost during the failure. The optical cross-connect (OXC) technology is an attractive alternative for fast restoration, and has the potential to provide bandwidth-management capability in future wavelength-division multiplexing (WDM) networks. This paper describes newly developed OXC systems with a low insertion loss of 1.16 dB and a high-speed restoration of <150 ms.

Cost-merit estimation of introducing optical layer with efficient traffic grooming

To quantify the cost merit of introducing an optical layer, we present an estimation of the number of electrical node equipments that can be saved by optical bypassing, using a novel method of computing efficient optical paths configuration.

Nonlinear optical properties of an InGaAs/InAlAs multiple quantum well waveguide with pulsed excitation

Large optical refractive nonlinearity in a passive InGaAs/InAlAs multiple quantum well waveguide is demonstrated at a wavelength of 1.55 /spl mu/m by observing a shift in the transmission fringe of a Fabry-Perot resonator with a pulsed pump beam. In a 650-/spl mu/m long resonator, a half /spl pi/ phase shift every 3.3 mW with increasing in pump beam power is observed up to 4/spl pi/. The response time of the nonlinear refractive index change is estimated to be 1 ns.<<ETX>>