Optium Corp., the Horsham optics equipment maker run by JDS Uniphase veteran Eitan Gertel, said today it's agreed to be bought by local-area networks compoment maker Finisar Corp., Sunnyvale, Calif., for around $212 million in a stock deal, pending shareholder approval.
  Gertel, a Drexel grad who's raising his family in the area, will run the combined companies as CEO.
  There's been no announcement on which town will be HQ, but Optium spokeswoman Veronica Rosa said the deal could mean more work for around 250 programmers, designers and managers in Horsham.
   Optium outsources manufacturing, while Finisar still does some of its own, though that's under review, company officials told investors in a morning conference call.