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A Y-00 transceiver for quantum encryption communication systems employing the Yuen-2000 protocol based on optical intensity modulation, which utilizes the quantum effect of coherent light has been developed and tested in field experiments. These experiments involved repeated transmission over a 192-km line on an existing commercial optical communication network with a bit-rate of 2.5 Gb/s based on STM-16 or OC-48. In addition, the affinity of the developed system for existing networks and communication protocols (Gigabit Ethernet and Fibre Channel) was examined. Subsequently, three optical fiber amplifiers were inserted as intermediate repeaters to give a non-repeated transmission distance of 48 km. The bit error rate after 192-km transmission was 10^-12 with an optical power of -19.4 dBm at the receiving end. In addition, it was confirmed that if an eavesdropper increased the received optical power, the bit error rate converged to about 5\times 10^- 1 and the identification of the true signal levels was virtually impracticable. These experimental results confirmed the high affinity between the Y-00 system and existing optical commercial networks and protocols used in the fundamental experiments. It was also apparent that the realization of highly secure optical communication networks was feasible. The performance of the Y-00 transceiver can be expected to improve to meet the strictest security evaluation. [ABSTRACT FROM PUBLISHER]

A 10-Gb/s optical transceiver using the Yuen 2000 (Y-00) encryption protocol was developed. The key device in the transceiver, a 10-GS/s, 10-bit digital-to-analog converter (DAC) LSI, was fabricated using 0.25-\mum SiGe BiCMOS technology. Circuit techniques such as segmented architecture, parasitic capacitance separation using the base-common transistor, and the usage of a common mode logic (CML) driver were employed to minimize glitches. The Y-00 transceiver equipped with the DAC LSI operated at 10 Gb/s. Moreover, a 300-km transmission experiment performed at a data rate of 10 Gb/s proved that the developed transceiver can be used in a practical application when forward error correction is applied. [ABSTRACT FROM PUBLISHER]

We developed the RHiNET-2/SW high-speed network switch for a high-throughput parallel computing system consisting of optically interconnected distributed personal computers (PCs). RHiNET-2/SW enables high-throughput network switching (64 Gbit/s) by means of a switching LSI and eight pairs of synchronized parallel optical interconnection modules. To confirm the reliability of RHiNET-2/SW, we measured its bit error rate (BER), which was less than 10-11 (estimated value: 10-20). Five RHiNET-2/SWs and sixteen PC nodes can perform parallel computing. This result demonstrates the feasibility of optical interconnection in a high-speed, flexible network in a parallel computing system. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 85(6): 1–10, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10022 [ABSTRACT FROM AUTHOR]