Opnext Joins the Tunable XFP Race
Alas, the parts couldn't be prepared in time for an OFC/NFOEC demo. Opnext will do the next best thing by showing the transmitter subassembly and present a paper explaining the design.
It's an important development, because the tunable XFP is arguably one of the hottest optical stories of 2011, and, until now, Opnext hasn't had one.
Meanwhile, the competition has gone giddy with tunable XFP announcements. JDSU (Nasdaq: JDSU; Toronto: JDU) was the first to launch and ship tunable XFPs, while Emcore Corp. (Nasdaq: EMKR), Finisar Corp. (Nasdaq: FNSR), Menara Networks and Oclaro Inc. (Nasdaq: OCLR) will probably all be showing devices -- and talking about them a lot -- at the conference. (See JDSU, Emcore Shrink Tunables, JDSU Ships Lots of Tunable XFPs, Finisar Shows Tunable XFP, Menara Intros Tunable XFP and Oclaro Demos Tunable XFPs.)
New entrants will be popping up, too -- Fujitsu Optical Components Ltd. introduced its tunable XFP just this week. (See Fujitsu Preps Tunable XFP.)
And now there's Opnext. The company plans to sample a tunable XFP module suitable for metro distances sometime this spring. A higher-performance model comparable to long-haul, 300-pin devices will be ready late this year or possibly early next year, says Jon Anderson, Opnext's director of technology programs.
"We're pretty late to market. We know this is the case, but we believe systems OEMs and carriers will find our tunable XFPs solve one of the main problems," Anderson says.
That problem is that as the laser tunes to the desired frequency, it passes through all the other frequencies on the way. If one of those other frequencies happens to be in use, that's going to cause interference. It's analogous to turning the dial on a radio (the kind that had dials, anyway) -- unwanted bits of each station come through the speakers.
A common way to avoid this is to shut off the laser during tuning. Opnext's approach involves using an optical shutter instead. More specifically, it uses the module's semiconductor optical amplifier (SOA) to dampen the signal so that it doesn't get out onto the fiber.
Tunable XFPs typically have an SOA inside, but many designs position it in front of a wavelength locker, "so they really need it in place in order to complete the tuning of the wavelengths," Anderson says. Opnext's design places the SOA as the final element that light passes through before hitting the fiber, freeing the SOA to do the optical shuttering trick.
— Craig Matsumoto, West Coast Editor, Light Reading