"Are these dividends not profits from OE's, but something else?"

Dividends are not profits; I have not read the agreement but assuming this clause is the only one related to POET it effectively means there is no expectation of revenue or income going directly to POET.

Dividends are a means of distributing after tax profits to shareholders.  The revenues/profits can remain in the company for as long as needed for ongoing operations/growth, but as soon as they choose to distribute profits - which is discretionary both in timing and amount- then 48.5% of what they pay out goes to POET.  

As an example using completely made up numbers - if they make 100 million dollars in after tax profit, they might keep 60 in the company to invest in future growth, and pay out 40 as a dividend so the owners/shareholders can get paid - from this 19.4m would come to POET.  I have no insight into the actual amount they might pay - it could be 100% of profits annually (though seems unlikely), nor the frequency or likelihood of them paying a dividend at all as it would depend on a myriad of market and operational variables