Oclaro has demonstrated a CFP2 coherent optical module at OFC 2014. To fit within the small pluggable form factor, two optical components have been developed: a transmitter package that combines two tunable lasers and an external modulator, and a micro integrated coherent receiver (micro ICR).
Having a 100G coherent CFP2 will enable equipment makers to double their 100G line card densities. However, given the module’s power constraints, the coherent DSP-ASIC will need to reside on the line card.
Oclaro’s optics for the CFP2 will also be used for its 100G coherent CFP module currently under development. “If you combine the [transmitter and micro ICR] optics, you get the CFP2, and the power target is 12W,” said Robert Blum, director, product management, at Oclaro. “Combining the optics with a [coherent] DSP in the CFP, the power target is 32W, the highest CFP [power] class.”
Having the DSP within the module simplifies the line card design and adds flexibility: the same CFP port can be used for line-side or client-side modules. But given that the coherent optics consumes 12W, the next-generation DSP-ASICs must consume no more than 18W to fit within a CFP.
Oclaro’s coherent CFP is expected by year-end, coinciding with a new generation of designs from merchant DSP-ASIC suppliers. ClariPhy Communications is sampling its LightSpeed-II devices, implemented using a 28nm CMOS process, while NTT Electronics (NEL) is developing its next-generation DSP-ASIC, which is rumoured to use an even more advanced process.
First samples of the coherent CFP2 will be with Oclaro’s customers in the second quarter, with general availability targeted for year-end 2014.
By Roy Rubenstein
Press release: Oclaro’s OFC Product Line-Up to Feature 100G Solutions with Higher Densities, Lower Power and Smaller Form Factors