Petaluma's Cyan Optics, which makes technology for broadband networks, has been named one of the most promising startups in the IT sector by the Wall Street Journal.

Five-year-old Cyan ranked sixth on the Journal's list of top 50 venture-backed companies.

The designation is "an exciting confirmation of our significant contributions to network transformation," Cyan CEO Mike Hatfield said Monday.

The Journal noted Hatfield's co-founder role at Calix, another Petaluma telecom equipment maker that went public last year with an $82 million stock offering.

Cyan's optical transport platforms help telecom providers deliver voice, video and data over their wireless and wireline networks.

It has about 100 employees and has raised more than $90 million in venture capital, including $30 million in last year's fourth quarter.