Tadashi Ikeuchi

A Single-40 Gb/s Dual-20 Gb/s Serializer IC With SFI-5.2 Interface in 65 nm CMOS

This paper presents a 40 Gb/s serializer IC in 65 nm bulk CMOS technology. The IC has an SFI5.2-compliant 10 Gb/s input interface and supports two different output modes, single 40 Gb/s for OC-768 VSR and dual 20 Gb/s for DQPSK. The IC is evaluated on a PCB and error-free operation is confirmed. The chip consumes 1.8 W for the 40 G mode, and 1.6 W for the 20 G mode from 1.2 V and 3.3 V power supplies.

Cost-effective low-loss flexible optical engine with microlens-imprinted film for high-speed on-board optical interconnection

There is a strong demand for optical interconnection technology to overcome bandwidth bottlenecks in high-end server systems. The interconnection speed in present systems is approaching 10 Gb/s, and higher-speed interconnections over 25 Gb/s are being discussed. To achieve such optical interconnections in commercial production, it is necessary to develop lower-cost and higher-speed optical transceiver modules. We propose a flexible printed circuit optical engine (FPC-OE) with a microlens-imprinted film and a polymer waveguide to achieve low-cost and high-speed operation. The microlens-imprinted film can be produced at low cost by using nanoimprint technology and can drastically reduce the optical loss of the FPC-OE with polymer waveguide. We successfully demonstrated error-free operation at 25 Gb/s with the fabricated optical transceiver that contains an FPC-OE, microlens-imprinted film, and a polymer waveguide.

A 3 Watt 39.8–44.6 Gb/s Dual-Mode SFI5.2 SerDes Chip Set in 65 nm CMOS

A Dual-mode 2 ×21.5-22.3 Gb/s DQPSK or 1 × 39.8-44.6 Gb/s NRZ to 4 × 9.95-11.2 Gb/s SFI5.2-compliant two-chip SerDes for a family of 40 Gb/s optical transponders has been fabricated in 65 nm 12-metal CMOS. By demultiplexing to 16 × 2.5 Gb/s internally, all logic and testability functions could be implemented in standard-cell CMOS, resulting in total power consumption of 3 W, 75 % lower than commercial BiCMOS SFI5 40 Gb/s SerDes ICs. Chip area is 4 × 4 mm, and the ICs are flip-chip mounted into a quad flat-pack package.

Optical interconnect architecture for servers using high bandwidth optical mid-plane

We describe an interconnect architecture that utilizes high bandwidth optical mid-plane. Enabling technologies for high density optical mid-plane are discussed. We developed a prototype to determine the feasibility. The results showed proposed architecture is practical.

30-Gb/s VCSEL transmitter fabricated on flexible printed circuit substrate

A VCSEL transmitter was fabricated on an flexible printed circuit substrate. The transmitter achieved clear eye opening with an extinction ratio of 4.6 dB and error-free operation at 30-Gb/s, demonstrating the applicability of the FPC for high-speed transmitter applications.

Vertex-centric computation of service function chains in multi-domain networks

Computation of service function chains in multi-domain networks is critical for enabling the wide deployment of network function visualization for providing end-to-end network services. In this paper, we present a vertex-centric distributed orchestration framework for multi-domain networks, in which physical infrastructure information is maintained locally within each domain without infrastructure information sharing between domains, so that the management and control of multi-domain networks can be significantly simplified. We also propose a distributed computing algorithm for mapping a service function chain request in multi-domain networks. Our objective is to find all feasible mappings, from which we can further prune to obtain the optimal solution satisfying different constraints and policies. We implement the proposed algorithm in an open source vertex-centric distributed computing system and simulate two practical network topologies to evaluate the performance, including signaling delay, message overhead, and computation time. Simulation results demonstrate superior efficiency and scalability of the proposed algorithm.

FPC-based compact 25-Gb/s optical transceiver module for optical interconnect utilizing novel high-speed FPC connector

A compact (22.6 × 9.1 × 0.86 mm), 25-Gb/s, flexible printed circuit based optical transceiver module was developed. The module consists of a 25-μm-thick FPC substrate on which a vertical-cavity surface-emitting laser array, driver, photodiode array, and a transimpedance amplifier are mounted by flip-chip bonding. The polymer waveguide is laminated from the backside of the FPC via microlens-imprinted film for the optical coupling. Its compactness and high-speed characteristics were realized by using a 0.35-mm-pitch novel FPC connector accurately designed by using a three-dimensional electromagnetic simulation. It was confirmed that the bandwidth of the FPC connector was more than 40 GHz. Also the measured results of the frequency response corresponded with the simulation results. Clear eye openings and error-free operation of all eight channels at 25 Gb/s were obtained with the fabricated optical transceiver.

Cost-effective optical transceiver subassembly with lens-integrated high-k, low-Tg glass for optical interconnection

Optical interconnection is a key technology to overcome bandwidth bottlenecks in high-performance computing and high-end servers. An optical subassembly that consists of a transparent substrate and optical devices is attractive for optical interconnection owing to the ease of optical coupling between an integrated lens and optical devices. However, there are difficulties associated with the fabrication of the substrate. To solve these problems, we propose an optical transceiver subassembly using high-k, low-Tg glass. The transceiver subassembly helps in overcoming not only the difficulty in processing conventionally used substrates but also the limitation on high-speed signal transmission by the coplanar waveguide on those substrates. We successfully demonstrate error-free operation at 10 Gb/s and 14 Gb/s with the fabricated optical transceiver subassembly that contains a vertical-cavity surface-emitting laser (VCSEL) array, a driver array, a photodiode (PD) array, and a transimpedance amplifier (TIA) array.

Efficient all-optical wavelength converter placement and wavelength assignment in optical networks

We propose an all-optical converter placement/wavelength assignment scheme to improve network utilization under practical constraints such as input wavelengths and cascadability. We show doubling of utilization compared to no conversion and 70% reduction in converters over OEO.

Double-sided-mount card-edge-connected optical transceiver module using cost-effective FPC-OE optical engine

We developed an 8-channel optical transceiver that achieves high density and low cost by adopting cost-effective FPC-OEs on both surfaces of a card-edge module. Clear eye-openings and error-free operation up to 14 Gb/s were obtained.