Cisco silicon photonics move a surprise

OvumAt OFC/NFOEC 2013, Cisco presented a silicon photonics modulator with integrated driver that competes with potentially both LiNbO and InP modulators for 100G coherent.
 
The move took many attendees – including me – by surprise. Silicon photonics for client-side 100G has been watched with great attention because there is no satisfactory solution. Coherent line-side, in contrast, has not one but two modulator solutions already. How can a third technology platform wedge its way in, and why?
 
On the other hand, in retrospect, we should have seen that this application is a great fit for silicon photonics. Low power modulation is what silicon photonics is best at. Since the beginning Lightwire, now part of Cisco, has used the same Mach-Zehnder device structure that line-side is already using. It has always said the driver, already in silicon, could be integrated with the modulator if it made sense.
 
The next generation of 100G line-side looks to use InP for size reduction into CFP and CFP2 densities. However, many believe the highest-performance versions might have to remain in LiNbO.
 
If the SiP modulator can deliver the performance, it would avert the issue of having a mix of high density and low density in system offerings. If it can further deliver the price and hybrid integration with the laser, the industry could eventually reconverge on a single external modulation platform.
 
The device has yet to have commercial-grade packaging and other productization done. But it does show how silicon photonics can compete simply on its true strengths rather than hype about large-scale integration.
 
Karen Liu is a principal analyst for components at Ovum. For more information, visit www.ovum.com/

Suggested Articles

Wireless operators can provide 5G services with spectrum bands both above and below 6 GHz—but that doesn't mean that all countries will let them.

Here are the stories we’re tracking today.

The 5G Mobile Network Architecture research project will implement two 5G use cases in real-world test beds.