Takuma Ban

A High-Coupling-Efficiency Multilayer Optical Printed Wiring Board with a Cube-Core Structure for High-Density Optical Interconnections

A multilayer optical printed wiring board with a cube-core structure was developed for high-density optical interconnections. A fabricated multilayer optical printed wiring board with this cube-core structure has optical-coupling efficiency 2.7 dB higher than one without this structure. A fabricated optical interconnection model successfully demonstrated 10-Gbit/s/channel operation. These results show that the advantage of this cube-core structure is that it provides high optical-coupling efficiency in a high-density multilayer optical printed wiring board.

25-Gbps receiver for 100-Gbps ethernet employing cost-effective small coaxial package

We developed a 25-Gbps receiver employing a small, cost effective coaxial package and flexible printed circuits. Our fabrication method for reducing electrical resonance and loss was effectively applied. The fabricated receiver had a 24-GHz 3-dB bandwidth and was successfully operated at 25 Gbps.

10 Gbit/s per channel parallel optical transmitter and receiver modules for high-capacity interconnects

We used a channel-pitch conversion structure to suppress inter-channel crosstalk in 4-channel x 10-Gbit/s parallel optical transmitter and receiver modules for use in highcapacity optical interconnection. Error-fkee transmission with the total throughput of 40 GbiUs over 600 m was successfully demonstrated. 1. Introduction The rapidly increasing volume of data tra& requires the use of cost-effective high-capacity optical interconnection between routers and fiber-transmission equipment in a same building. A parallel optical link is one of the best solutions for such very-short-reach (VSR) applications because of its simple and cost-effective configuration. Many vendors have been developing various configurations for parallel optical links made by ribbon fiber, such as 4- and 12-channel x 2.53.125-GbiUs transmitters and receivers (with a total throughput of 12.5-30 Gbitls) [I, 21. In the near future, parallel optical links with a total throughput of 40 GbiUs and beyond will be needed. One way to achieve veIy highcapacity transmission is to use parallel optical interconnection with a transmission speed of 10 GbiUs per channel [3]. A 4channel configuration [4] with 10-GbiUs channels has enabled all-duplex transmission with a simple single 8-channel ribbon-fiber cable. However, strong inter-channel crosstalk at the high per-channel rate makes multi-channel operation at this rate impracticable. To suppress the inter-channel crosstalk in a parallel architecture, we have developed a channel-pitch conversion structure based on a polymer planar lightwave circuit (PLC) platform, and demonstrated 4-channel x 10-GbiUs parallel transmitter and receiver modules [5-71. In this paper. we describe the characteristics of the fabricated transmitter and receiver modules. We also report on our successfid demonstration of error-free 10GbiUskhannel transmission with the total throughput of 40 Gbitk over 600 m (VSR) and an optical power budget of more than 6 dB.

High-performance PIN photodiodes with an integrated aspheric microlens

We describe an aspheric-microlens-integrated high-performance PIN photodiode, which exhibits high speed (35 GHz), high responsivity (0.8 A/W), and large alignment tolerance (26 µm) for direct coupling to a flat-ended standard single-mode fiber.

1.3-

A four-channel times10-Gb/s parallel optical transceiver for high-capacity very-short-reach applications was developed. The transceiver module was fabricated with low-cost components such as polymer planar lightwave circuit (PLC) platforms and 1.3-mum Fabry-Perot laser diodes (FPLDs). The polymer PLC platform enables the FPLDs or waveguide photodiodes (WGPDs) to be butt-coupled to the polymer waveguide by low-cost passive alignment. Using 1.3-mum FPLDs and single-mode fibers (SMFs) achieves reliable transmission over 600 m. Widening the spacing between the waveguides up to 1 mm suppressed the interchannel crosstalk to below -39 dB. The fabricated transceiver was operated at 10 Gb/s per channel and it successfully demonstrated 600-m error-free transmission. The sensitivity of each channel was better than -14 dBm with an interchannel-crosstalk penalty of less than 0.7 dB

mu

4 ch × 25.8 Gbit/s WDM transmission over 40 km single mode fiber was demonstrated. Minimum receiver sensitivity each lane after 40 km transmission was less than −26.0 dBm, proving the transceiver will meet IEEE 100GBASE-ER4 specifications.

m Four-Channel

We developed a four-channel × 10-Gbit/s parallel optical transceiver with a height of only 6.5 mm. The fabricated transceiver was operated at 10 Gbit/s per channel and exhibited error-free 100-m transmissions using conventional multimode fibers.