ORC Seminar Series

"Planar Lightwave Circuits for FTTH and Photonic Networks"


Professor Katsu Okamoto
Department of Electrical and Computer Engineering, University of California

Date: Thursday 6 December 2007
Time: 11.30am
Venue: Building 46, Lecture Theatre C


Integrated-optic waveguide devices become more and more complicated to realize high functionality. Channel numbers of AWGs have been dramatically increased up to 400ch in single wafer. In the multi-chip configuration, 4200ch has been achieved with 5GHz channel spacing.

Although optical technologies are replacing most transmission lines, the nodes of the networks, such as switching and cross-connect nodes, are still depend on electrical technologies. Introducing the optical functional devices into node of networks is important to solve the electrical bottleneck issues.

Various kinds of optical-layer signal processing devices have been developed; they are reconfigurable optical add/drop multiplexers (ROADM), wavelength selective switches (WSS), dispersion compensators, PMD equalizers, dynamic gain equalizers, optical label recognition circuits, temporal pulse waveform shapers, and etc.

Ultra-compact and CMOS compatible silicon waveguides are important for the integration of an optical component and an electronic circuit aiming at higher level of functionalities.

The talk reviews the recent progress and future prospects of waveguide devices and their applications to trunk communication systems, FTTH access networks, photonic signal processing, and possible sensor applications.


Dr. Okamoto was born in Hiroshima, Japan, on October 19, 1949. He received the B.S., M.S., and Ph.D. degrees in electronics engineering from Tokyo University, Tokyo, Japan, in 1972, 1974, and 1977, respectively.

He joined Ibaraki Electrical Communication Laboratory, Nippon Telegraph and Telephone Corporation (NTT), Ibaraki, Japan, in 1977, and was engaged in the research on transmission characteristics of multimode, dispersion-flattened single-mode, single-polarization (PANDA) fibers, and fiber-optic components. He proposed for the first time the dispersion-flattened fiber (DFF) and succeeded in fabrication of DFF that had chromatic dispersion less than +/-1 ps/km/nm over a wide spectral range.

From September 1982 to September 1983, he worked at Optical Fiber Group, Southampton University, where he was engaged in the research on birefringent optical fibers.

From October 1987 to October 1988, he stayed at RCAST (Research Center for Advanced Science & Technology) of University of Tokyo as Associate Professor with Dr. E. A. J. Marcatili from AT&T Bell Laboratories. Dr. Marcatili was invited as a guest professor of the endowed chair at RCAST. They studied the influence of nonlinear optical effects on propagation characteristics of optical fibers. Along with research activities they taught electromagnetic theory, optoelectronics and fiber optics at Electronics and Applied Physics Department.

Since 1990, he has been working on the analysis and the synthesis of guided-wave devices, the computer-aided-design (CAD) and fabrication of silica-based planar lightwave circuits (PLCs) at Ibaraki R&D Center, NTT Photonics Laboratories. He developed a CAD tool based on the beam propagation method and a FEM waveguide and stress analyses. The design tool for arrayed-waveguide grating (AWG) filter is widely utilized in NTT Photonics Laboratory and its subsidiary company (NEL). He has developed a 256x256 star coupler, various kinds of AWGs ranging from 8ch-300nm spacing AWGs to 128ch-25GHz AWGs, flat spectral response AWGs and integrated-optic reconfigurable add/drop multiplexers. 200 GHz to 50 GHz spacing AWGs are now widely used in the commercial WDM systems.

In 2003, he started Okamoto Laboratory Ltd. Okamoto Laboratory is a R&D consulting company that deals with the custom design of optical fibers and functional planar lightwave circuits.

From July 2006, he serves as Professor of Electrical and Computer Engineering at the University of California at Davis (UC Davis). His research at UC Davis includes passive and active photonics devices for high-performance all optical networks.

He has published more than 250 papers in technical journals and international conferences. He authored and co-authored 8 books including “Fundamentals of Optical Waveguides, 2nd ed. (Elsevier)”.

Dr. Okamoto is a member of the Institute of Electrical and Electronics Engineers (Fellow), Optical Society of America and the Institute of Electronics Information and Communication Engineers of Japan.


Copyright University of Southampton 2006