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We demonstrate fundamental functions for ultrafast optical routing by using an elemental part of an ultrafast optical technique for conversion of time to two-dimensional space. A preliminary experimental result shows that recognition of header signals can be achieved at a rate of more than 600 Gbytes/s.

Using a commercially-ready 40-DWDM system, RZ-DQPSK is confirmed to offer excellent DGD tolerance, up to 25 ps, through high PMD installed DSFs.2006 Optical Society of America OCIS codes: (060.0060) Fiber optics and optical communications; (060.5060) Phase modulation IntroductionThe explosion of Internet traffic is strengthening the demand for high capacity backbone networks. 43Gbit/s technologies are very attractive for constructing high-capacity backbone networks based on Dense Wave-length Division Multiplexing (DWDM) because 43Gbit/s technologies offer better spectral efficiency. They also reduce equipment size and are suitable for cost-effective mass-production. Moreover, 43Gbit/s DWDM systems simplify network management by reducing the number of multiplexed channels compared to systems based on 2.4 or 10 Gbit/s channels. However, the many impairment factors include non-linear effects, chromatic dispersion, and polarization mode dispersion (PMD). PMD is an especially important factor in limiting the transmission distance. PMD is regarded as birefringence with a differential group delay (DGD) caused by dual path propagation in the fiber; it produces intersymbol interference. RZ-DQPSK is an very attractive modulation format [1,2] because of its large PMD tolerance; its timeslot is twice as long as that of the binary modulation format. Thus, RZ-DQPSK will be employed in a commercial 43 Gbit/s 40 DWDM system being developed to deploy in NTT's terrestrial network by 2007/1Q. Target transmission distance of the system is over 500 km with installed fibers. (A spectrum of 40 transponders after 480 km transmission is shown in Fig.1.) In this paper, we describe mean DGD fluctuation of the installed fibers and clarify that RZ-DQPSK is the most appropriate modulation format for practical 43Gbit/s DWDM systems from the viewpoint of PMD tolerance. We use a 43 Gbit/s transponder of the system being developed to confirm the large PMD tolerance of RZ-DQPSK with high DGD installed fibers.