Transceiver offers high-throughput connections

A collaboration between Fujitsu Components and Fujitsu Laboratories has simplified the structure and assembly of a transceiver.

A collaboration between Fujitsu Components and Fujitsu Laboratories has resulted in the development of a three-dimensional (3D) polymer optical waveguide and a bidirectional, four-channel optical parallel transceiver using the 3D polymer optical waveguide as an optical integration platform, which simplifies the structure and assembly of the transceiver.

The new transceiver combines a low-cost, optical parallel link solution with a high-speed electrical interface to handle 3.125Gbit/s data transmission up to 300m, 5Gbit/s up to 100m over standard, multimode ribbon fibre with 850nm wavelength.

Designed for very short reach (VSR) applications, the new transceiver delivers scaleable, high-throughput connections within and between racks, shelves, and boards of optical networking equipment in central offices and large enterprises.

The waveguide was successfully developed using Fujitsu Component's precise injection moulding technology and Fujitsu Laboratories' optical design and process technology.

It is composed of a base structure (clad) with rectangular grooves filled with core material covered with overclads, and an integrated microlens arrays.

The waveguide has multiple functions such as optical coupling between VCSELs (vertical cavity surface emitting lasers)/PIN photodiodes and the waveguide, optical coupling between the fibres and the waveguide, lightbeam bending and guiding between VCSELs/PIN photodiodes and fibres mounted at right angles to each other, and a structural base for mechanical and optical configuration integrity.

Optoelectronic array devices, ICs and electric traces can also be mounted beneath the waveguide on a single, small circuit board.

This eliminates the use of a separate subcircuit board for an optical subassembly and contributes to optimising electrical design for high-speed circuit operation and high signal integrity.

The polymer waveguide technology has a wide range of applications that feature low cost and scalability in parallel or functional integration of optical elements or functions.

These include waveguide pitch or height conversion, channel count expansion, optical directional coupling, and horizontal or vertical optical routing.

Along with the progress of polymeric materials with electro-optical or thermo-optical effects, the technology will also be applied to more sophisticated functional devices such as variable optical attenuators, modulators, and optical switches.

The new optical parallel transceiver incorporates a four-element, 850nm VCSEL array lit by a driver IC, a four-element PIN photodiode array coupled with a receiver IC, and a control IC for driver and receiver ICs.

It has eight independent channels (four transmitters and four receivers) and a 12-fibre multipath optical (MPO) connector output interface.

It works with 0.9W power consumption (3.3V) over the operating case temperature range of 0 to 70C.

The receive portion of the module uses an industry standard, hot-pluggable MDI connector electrical interface (Fujitsu's microGiGaCN) for high-speed copper transmission.

The bit rate-transparent and application-agnostic transceiver is compatible with SDR (2.5Gbyte a second), DDR (5.0Gbit/s) InfiniBand 4X and Fibre Channel (3.1875Gbit/s) systems, as well as 10GBase-CX4.

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