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The article discusses optical fiber and cable maintenance and operation technologies being developed by Nippon Telegraph and Telephone Corporation Access Network Service Systems Laboratories to support full-scale fiber-to-the-home broadband service in Japan. The addition to passive optical network architecture of ultrahigh capacity fiber is said to be facilitated by route switching techniques while space division multiplexing is considered a potential solution to capacity limitation.

T2K is a second generation long-baseline experiment in Japan, designed to perform precision studies of neutrino oscillations. A neutrino beam originating at the J-PARC facility is sampled by two near detectors, approximately 280 m distant from the source and directed towards the Kamioka underground facility, 295 km distant, where the Super-Kamiokande water Cerenkov detector is situated. Both the on-axis (INGRID) and off-axis (ND280) near detectors employ the MIDAS framework for their data acquisition systems. Events are selected via a flexible hardware trigger, which allows mixed operating modes incorporating beam spill, cosmic and calibration triggers. Data are acquired from the front-end electronics over optical Gigabit Ethernet links by custom MIDAS front-end applications distributed over a cluster of Linux computers. Event fragments from all sub-detectors are merged and logged on a central backend processor and then copied to remote storage for long-term archival. The system is also designed to allow flexible partitioning of sub-detectors for standalone diagnostics and calibration. We present the design of the DAQ system and report on experience gathered during early operation of the near detectors. [ABSTRACT FROM PUBLISHER]

A light source and optical frequency control technique needed for realizing the optical frequency division multiplexing transmission (Optical FDM) is developed and experiments of a 622 Mbit/s-sixteen-channel FDM coherent optical transmission based on the heterodyne detection are conducted. The transmission is configured such that sixteen 1.55 μm wavelength two-section MQW DFB-laser diode (LD) are multiplexed by a star coupler. The wavelength of each LD was spaced at 10 GHz intervals with the frequency fluctuation kept trader ±100 MHz by the optical frequency control circuit that uses a scanning Fabry-Perot interferometer. The receiver configuration has a delay-line demodulator, polarization diversity, and a frequency discriminator with no dead bands. For the station light source, the two-section MQW DFB-LD was tuned, which is the same as the transmitter, using current and temperature control. Random channels could selectively be received with a receiver sensitivity of -39.3 dBm. It was verified that 16 channels of 622 Mbit/s high-vision (Japanese standard HDTV) signal could be transmitted through 110 km of 1.3 μm zero dispersion fiber without signal degradation. [ABSTRACT FROM AUTHOR]

The article focuses on the highlights of the 36th annual European Conference on Optical Communication (ECOC) held in Turin, Italy in September 2010. The goals of ECOC include the dissemination of new research results, the education of engineering and business leaders and the exhibition of optical fiber communication and networking products. Speakers at the event included Masataka Nagazawa of Tohoku University in Japan, who discussed developments related to optical communication technologies.