Here is a link to Bloomberg's report on Apple's new datacentres. Could POET's VCSEL be part of the top of the rack switch?

http://www.bloomberg.com/news/articles/2015-06-08/apple-said-to-build-high-speed-network-for-fast-content-delivery

Cupertino, California-based Apple isn’t expected to replace the hundreds of thousands of servers and other machines in its current data centers, but will use more of its own gear as it builds new facilities. Earlier this year, Apple said it would spend $3.9 billion on new data centers in Arizona, Ireland and Denmark. It’s working on at least one product, called a top-of-rack switch, using open-source software from startup Cumulus Networks Inc. running on servers made by Taiwan-based Quanta Computer Inc., said two people with knowledge of the plan.

Cisco's TOR http://www.cisco.com/c/en/us/products/collateral/switches/nexus-5000-series-switches/white_paper_c11-522337.html