This paper describes design techniques for suppressing crosstalk in an optical transceiver module using PLC-hybrid-integration technologies and for achieving burst-mode operation with high sensitivity and wide dynamic range using CMOS-IC technologies. An arrangement that reduces the electrical crosstalk to less than -100 dB was designed using three-dimensional electromagnetic field analysis. The configurations of a newly developed instantaneous-response CMOS LD driver circuit is also described and instantaneous-response CMOS receiver circuit techniques are reviewed. With these techniques, we have succeeded in building optical transceiver modules for ATM-PON systems using PLC-hybrid-integration and inexpensive standard CMOS-IC fabrication processes. Under full-duplex operation at 156 Mb/s, fabricated transceiver modules showed receiver sensitivity of better than -34 dBm and dynamic range of over 28 dB, which satisfy both the class-B and class-C specifications recommended by ITU-T (International Telecommunication Union-Telecommunication standardization sector) G983.1 for the optical transceiver module for an ONU (optical network unit).

Although the Internet is playing an increasingly significant role in global communication, it remains vulnerable to malicious traffic such as worms and DoS/DDoS attacks. In the last few years, the emergence of high speed active worms, such as Code Red II, Nimda, SQL Slammer and MS Blaster, has become a serious issue. These worms cause serious damage to communication networks throughout the world by using up network bandwidth. In addition, since conventional firewall systems are located just in front of the server and do not prevent malicious traffic from entering the network, they cannot prevent such network congestion. Therefore, the firewall between domains or between core routers should play important roles in the photonic networks. We have developed a prototype system of a network firewall using reconfigurable processors. In this paper, we overview the developed system and present its evaluation results.

This paper describes design techniques for suppressing crosstalk in an optical transceiver module using PLC-hybrid-integration technologies and for achieving burst-mode operation with high sensitivity and wide dynamic range using CMOS-IC technologies. An arrangement that reduces the electrical crosstalk to less than -100 dB was designed using three-dimensional electromagnetic field analysis. The configurations of a newly developed instantaneous-response CMOS LD driver circuit is also described and instantaneous-response CMOS receiver circuit techniques are reviewed. With these techniques, we have succeeded in building optical transceiver modules for ATM-PON systems using PLC-hybrid-integration and inexpensive standard CMOS-IC fabrication processes. Under full-duplex operation at 156 Mb/s, fabricated transceiver modules showed receiver sensitivity of better than -34 dBm and dynamic range of over 28 dB, which satisfy both the class-B and class-C specifications recommended by ITU-T (International Telecommunication Union-Telecommunication standardization sector) G983.1 for the optical transceiver module for an ONU (optical network unit).

A hybrid integrated optical module composed of a silica-based planar lightwave circuit (PLC), a laser diode with an integrated monitor-photodiode, and a pin-photodiode is fabricated for use in high-performance, compact and cost-effective fiber optic subscriber systems. Its applicability to a wavelength-division-multiplex (WDM) system with a 1.3-µm bi-directional signal and a 1.5-µm one-way signal is demonstrated. The PLC was fabricated by a combination of flame hydrolysis deposition (FHD) and reactive ion etching (RIE), and it simultaneously achieved 1.3-µm/1.5-µm multi/demultiplexing and 1.3-µm Y-branching functions. The optical module exhibited insertion losses of 4.1dB at 1.31µm (including a Y-branch circuit loss of 3dB) and 0.5dB at 1.53µm. An optical output power of more than -4dBm was obtained from the optical module and the crosstalk was sufficiently low at less than -20dB between wavelengths of 1.3µm and 1.5µm. Temperature cycle tests on the optical module showed reliable and stable operation with an optical power fluctuation of less than 0.3dB for 500 cycles.