100G multimode active optical cable developed
At OFC 2014, Fujitsu Components Ltd. will exhibit its newly developed quad small form-factor pluggable (QSFP28) active optical cable (AOC) for high-speed data center networks.
Fujitsu Components Ltd. will exhibit its newly developed, quad small form-factor pluggable (QSFP28) active optical cable (AOC) for high-speed data transmission in booth #3445 at the upcoming OFC 2014 conference (March 9-13) in San Francisco.
According to the company, the QSFP28 AOC leverages a cost-efficient, four-channel optical transceiver that conforms to the QSFP28 multi-source agreement. The cable is capable of delivering 100-Gbps data rates over four lanes of 25 Gbps with a reach of up to 100 meters maximum. The AOC supports InfiniBand EDR and 100 Gigabit Ethernet (100GBase-SR4) transmission speeds and is best for close-range, high-speed transmission in data center networks, such as between servers and server racks, Fujitsu says.
The company claims the product is the world's first 100-Gbps AOC based on 4x25-Gbps channels over multimode fiber. Further, the QSFP28 AOC uses two new technologies developed by Fujitsu Laboratories Ltd.: overdrive technology and a next-generation high-speed optical engine structure.
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The overdrive technology enables 25-Gbps transmission speeds using existing 14 Gbps vertical-cavity surface-emitting lasers (VCSELs) by implementing a three-tap finite impulse response (FIR) pre-emphasis signal on the VCSEL driver. This is a modulation technique that increases the amplitude of certain frequencies in the signal in response to the attenuation feature at high frequency, allowing the VCSEL to run faster than normal.
The optical engine has three layers consisting of an optical waveguide sheet, a lens sheet, and a flexible printed circuit (FPC) board. The lens sheet is made with nano-imprint technology, and optical devices are flip-chip mounted on the board. Stacking each layer on the optical waveguide using passive alignment enables further cost reduction.
To ensure electric signal transmission speed, Fujitsu’s FCN-152J high-speed FPC connector series is used for connecting to the optical engine. Evaluation samples of the new cable are available now, with engineering samples available in June 2014.