Fiber optics — a highflying sector in the dot-boom that crashed hard in the dot-bomb — is back, riding the rising tide of video and other data traffic over networks. Shares of optical parts maker JDS Uniphase (JDSU) roared just like in the early dot-com days on Friday, jumping 25% in midafternoon trading after the company late Thursday reported Q4 results well above analyst views. JDSU's stock has soared 140% since August.