Advances in optical path crossconnect systems using planar-lightwave circuit-switching technologies

This article highlights advances in NTT's optical path crossconnect systems that use planar-lightwave circuit switches. A photonic MPLS router that can handle up to 256 optical label switched paths is developed as one result of our R&D activities; mature OPXC technologies are adopted to create a practical OPXC system.     

Reduction in risk of mortality from colorectal cancer by fecal occult blood screening with immunochemical hemagglutination test. A case-control study

Fecal occult blood testing by immunochemical hemagglutination has been shown to be superior to the Hemoccult test, both in sensitivity and in specificity. The test has been widely used as a tool for population screening in Japan, but there has been no study to evaluate the efficacy of screening using this test. A case-control study to evaluate the screening was conducted in study areas where no previous and no other concomitant colorectal cancer screening had been performed. Case series in the study were 193 cases who died of colorectal cancer. Three controls were selected randomly from the list of individuals who were alive at the time of diagnosis of the corresponding case and had been living in the same area as the case, matched by gender and by age. Odds ratios (OR) of dying of colorectal cancer for those screened within 1, 2 and 3 years of case diagnosis vs. those not screened were 0.40 [95% confidence interval (CI) 0.17-0.92], 0.41 (95% CI 0.20-0.82), and 0.48 (95% CI 0.25-0.92), respectively. OR increased towards 1.0 as the duration during which screening histories were compared was extended, and showed similar tendencies when analyzed by number of years since the most recent screening history. These results suggest that colorectal cancer screening by the immunochemical fecal occult blood test would reduce mortality from colorectal cancer.     

Fully transparent multiplexing and transport of 10 GbE-LANPHY signals for 44.6 Gbit/s-based RZ-DQPSK WDM transmission

Transparent 10 GbE-LANPHY transport for 44.6 Gbit/s RZ-DQPSK WDM transmission is demonstrated for the first time. A single-chip 43/44 Gbit/s OTN framer LSI that supports fully transparent STM-64/10 GbE multiplexing and DQPSK precoding is adopted.     

Characteristics of Tantalum Surface Treated by 6-Triethoxysilylpropylamino-1,3,5-Triazine-2,4-Dithiol Using XPS

The characteristic of material surfaces has a vital status in its application,for instance,surface properties of materials play a decisive role in adhesion technology between different materials.A method called molecule adhesion technology which can successfully adhere different materials such as polymers,rubbers,metals and exhibit strong adhesion strength without any adhesive agents.In this work,the rare metal of tantalum surface treated by corona and a molecular adhesive(6-triethoxysilylpropylamino1,3,5-triazine-2,4-dithiols,TES)has been investigated to clarify the reaction mechanism between tantalum and TES.Chemical structures of surfaces treated by corona and TES were also analyzed.TES contains two functional groups:one is alkoxysilyl group which can react with the OH group linked tantalum formed by the corona discharge treatment;the other is dithiol triazinyl group reacted with many other materials.Blank tantalum,corona treated and TES treated surfaces situation were analyzed by X-ray photoelectron spectroscopy(XPS).The result shows that the functional structure of OH groups was formed after corona discharge process and TES can be successfully reacted on the tantalum surface.This research can be as a preparation work to achieve the tantalum and other materials adhesion by using molecule adhesion technology in the MEMS and NEMS electronic device fields.     

A novel tuning method for a neural control WDM demultiplexer

A new channel selection sequence using a neural control WDM demultiplexer is proposed in packet-switched WDM network. This demultiplexer achieves demultiplexing through an electrically controlled neuro-circuit, thereby achieving fast tuning. In the tuning experiment for optical signals at three different wavelengths, tuning is completed in approximately 20 /spl mu/s. The channel switching function is also examined by experimentation.     

Reduction of four-wave mixing induced penalty in unequally spacedWDM transmission system by using optical DPSK

Optical DPSK signalling is employed in unequally spaced WDM transmission systems using dispersion-shifted fibres to reduce the penalty caused by four-wave mixing. More than 10 dB reduction in power penalty is achieved compared with the use of intensity modulation     

Intercalation of collagen and soybean peptides into Zn-Al layered double hydroxide

In order to develop a new type biocompatible organic/inorganic nanohybrid material, an intercalation of collagen peptides (CP) and soybean peptide (SP) into Zn-Al layered double hydroxide (LDH) by the coprecipitation reaction has been investigated. The peptide/LDH has been characterized by chemical analysis, powder X-ray diffraction (XRD), Raman spectroscopy, thermal gravimetric analysis (TG) and transmission electron microscopy (TEM). According to the XRD patterns and Raman spectra, the solid products were found to contain peptide and to show broad diffraction peaks with LDH structures. The CP/LDH and SP/LDH possess the expanding LDH structure, d(00l) = 2-3 nm, confirming that both peptides were intercalated into the LDH interlayer space with low organized stacking arrangement.     

A 1580-nm band WDM transmission technology employing opticalduobinary coding

This paper reports 1580-nm band wavelength division multiplexed (WDM) transmission employing optical duobinary coding over dispersion-shifted fibers. By using the 1580 nm band, the generation of four-wave mixing (FWM) over dispersion-shifted fibers (DSFs) can he suppressed. Optical duobinary coding is dispersion-tolerant because of its narrow bandwidth, and enables the use of the conventional binary intensity modulated direct detection (IM-DD) receiver. First, comparisons are made for WDM transmission performance in the 1580-nm band between conventional binary nonreturn-to-zero (NRZ) coding with and without postdispersion compensation, and optical duobinary coding by computer simulation is described. From the numerical simulations, it is found that the optical duobinary coding has superior transmission performance to the conventional binary coding without any dispersion compensation, and that the difference in the transmission performance between two coding methods is very small even if postdispersion compensation at the optical receiver is applied to the NRZ coding method. Second, transmission performance between the conventional binary NRZ and the optical duobinary signals without any dispersion compensation is compared with the straight-line experiment over 500-km dispersion-shifted fiber. The experimental results reveal that the transmission distance with optical duobinary coding is doubled in comparison with that of the conventional binary NRZ signals. Finally, 16-channel, 10-Gb/s optical duobinary WDM signals in the 1580-nm band are successfully transmitted over 640 km (80 km×8) of DSF without any dispersion compensation or management     

Learning method for neural networks using weight perturbation oforthogonal bit sequence and its application to adaptive WDMdemultiplexer

This paper proposes a novel on-chip learning method for hardware-implemented neural networks to achieve an adaptive wavelength division multiplexer (WDM) demultiplexer. The parameters of the neural network are perturbed by orthogonal bit sequences with small amplitude. The parameters are corrected based on the correlation detection result between the perturbed error signal and the corresponding perturbation signal. A learning experiment that transmits 200-Mb/s, four-channel WDM signals through a 40-km fiber and the tracking of the wavelength drift of the optical transmitter successfully demonstrate the proposed method