VCSELs Revisit OFC
Is a revival afoot in the Vertical Cavity Surface Emitting Lasers (VCSELs) market? Despite considerable challenges, a few companies would like to think so. At the OFC Conference last week, several companies discussed products that will be available by year's end.
Infineon Technologies AG (NYSE/Frankfurt: IFX) demonstrated its 1310nm VCSEL, dispelling rumors that the product had been scuttled last summer. And Picolight Inc. gave the first demonstrations of a 1310nm VCSEL that's been shown privately in the past.
Meanwhile, upstart E2O Communications Inc. continued to tout its plans for long-wavelength VCSELs, although the company's OFC presence was focused elsewhere, on 10-Gbit/s XFP modules (see XFP Gets the Fast Track).
Research on VCSELs has continued for more than a decade, and early products from the likes of Cielo Communications haven't made it to volume production (see Startups Carry VCSEL Flame and Tunable Lasers Revisited. VCSELs, which emit light from the surface of the component material rather than the edge, have advantages over traditional edge-emitting lasers in manufacturing and testing.
VCSELs at 850 nm have been shipping for some time, but the 1310nm parts have been slow to emerge. One concern has been output power, as early editions weren't strong enough to travel metro-like distances. Another problem is manufacturability, as many designs rely on difficult materials such as indium gallium arsenide nitride (InGaAsN). (See Laser Blazers.)
But plenty of companies still believe in 1310nm VCSELs, as shown by startup Lytek Corp. joining the race after the exit of such companies as Gore Photonics Inc. and Cielo. (For a rundown on who's out and who's in, see Lytek Takes On Laser Challenge.)
"The feeling has been that if these guys chip away and chip away, a breakthrough is possible," says Tom Hausken, analyst with Strategies Unlimited. "The thing that's tricky is you can demo output power, but you might not be able to manufacture it economically."
E2O's plans could be the most dramatic of the bunch, as the startup says it's gotten 6 mW of output power from its 1310nm VCSEL, exceeding the 4 mW that E2O announced in 2001 (see E2O Claims VCSEL Power Record).
So why wasn't the company showing off its laser on the OFC floor? Because it's not quite ready for sales, concedes CEO H.C. Lee. "If we cannot show high-yield manufacturability, we have no product," he says.
Lee hopes to have the 1310nm VCSEL ready by the end of the year. Sound familiar? "Two years ago, I said we were going to manufacture it by the end of the year," he admits. "This time, we have a better appreciation of the technology and a better handle on it.”
Infineon's situation is just the opposite, as officials at OFC crowed about being the first manufacturing-heavy company to produce a 1310nm VCSEL, but reported output power of just 0.4 mW. The company expects to take the parts to production early in the fourth quarter of 2003.
The device targets speeds of up to 2.5 Gbit/s and distances up to 15 km.
Infineon also used the new VCSEL to introduce its intelligent small-form-factor pluggable module (iSFP), which includes a serial interface for checking optical parameters or accessing performance reports. It's likely that all of the company's future VCSELs will get the iSFP treatment, says Jianmei Jia, Infineon product marketing manager.
Finally, Picolight demonstrated a 1310nm VCSEL transceiver in an SFP package. Picolight is adding the VCSEL-based device to its Extensus family of 1310nm products.
Picolight has been demonstrating the 1310nm part for a couple of years, but only privately. The company chose to do public demonstrations this year because it's gotten the VCSEL to meet key specifications for the access space, for standards such as OC3 and Gigabit Ethernet.
Picolight does expect to put VCSELs into metro reaches of 20 km or even 40 km, but the company will focus its 1310nm VCSEL on the access market for now. "That's where the volume is for a new laser, because it's an emerging market," says Warner Andrews, Picolight's vice president of marketing.
— Craig Matsumoto, Senior Editor, Light Reading
For up-to-date information about the OFC Conference, please visit Light Reading’s Unauthorized OFC Site.