The Lightwire purchase was done at time when silicon photonics was in its early stages of development. It was multimode at 10g. 

"The real purpose here for us, aside from our continued focus on the core [priorities], was to make sure we were on top of the 40Gbit/s and 100Gbit/s transition," says Hilton Romanski, Cisco's vice president of business development, whose job is to run Cisco's acquisitions and investments. (See Subtract Another Cisco Name.)

CISCO would later go on to purchase Luxtera and expand their development into silicon photonics.

POET is a total departure from these technologies and provides performance benefits and cost savings that have never been realised from typical silicon photonic platforms.

So what is POET's relative value? Whatever someone will pay to gain access to what may be a platform that can dominate all fields of  optical  integration for  the foreseeable future.