Shash:  In the midst of all this speculation, it might also be pertenant to keep in mind that Cisco, in the industry, is considered an "end user" company.

Cisco develops, manufactures and sells networking hardware, software, telecommunications equipment and other high-technology services and products. Wikipedia

And Poet is dealing with more than one according to their press release from Nov, 2018

SAN JOSE, CA, November 12, 2018 – POET Technologies Inc. (the “Company” or “POET”) (OTCQX: POETF; TSX Venture: PTK), a designer, developer and manufacturer of optoelectronic devices, including light sources, passive wave guides, and Photonic Integrated Circuits (PICs) for the data- and tele-communication markets, announced today that it has received its first orders for POET Optical Interposer™-based solutions from leading global communications companies targeting data communication applications, which represents a new served market for the Company’s products.

This, and the fact that Cisco was listed as a customer of one Denselight's senior engineers on his linked In profile. (according to ITTR).