October 2008 Archives

In the midst of the turmoil in the banking industry, and the seemingly endless stream of bad news from Wall Street, it's easy to get stuck in a negative mindset. But a couple of articles that I saw recently highlight the fact that one man's bad fortune can be another man's opportunity.

For a kickoff, Paul Graham, essayist and co-founder of Viaweb, the first application service provider, writes about why to start a start-up in a bad economy. Many folk are predicting that this economic slowdown could be as bad as the seventies, he notes... that's when Apple and Microsoft were founded.

Investment guru George Gilder also provides some welcome relief from the doom and gloom with an article in Forbes in which he talks about an upcoming creativity boom. "The real source of all growth is human ingenuity and entrepreneurship, which often thrive in the worst of times," Gilder points out. Which company emerged victorious from the telecoms crash of the early 2000s? Google.

A few more things I saw at ECOC are worth noting, albeit belatedly, and a bunch of them were about 40 Gbit/s components.

In his market focus presentation, Kim Papakos from Tellabs highlighted single source components as a real problem for systems vendors wanting to build 40 and 100 Gbit/s networking gear. Ideally companies like Tellabs would like at least three sources on the market, so that if one supplier goes belly up, there are still multiple sources available. That requirement is passed down to them from their operator customers.

Loi Nguyen and Lian Zhao from Inphi

The lack of suitable off-the-shelf parts for 40 Gbit/s has often been cited as one of the factors that delayed the adoption of 40 Gbit/s networking. Nevertheless, it surprised me to find that there are still quite a lot of 40 Gbit/s components that are only made by one company, and some that simply aren't available at all.

A case in point, Inphi and Sierra Monolithics joined forces to create the industry's first reference design for 40 Gbit/s DQPSK (differential quadrature phase-shift keying) modulation. The booth demo showed interoperability of Inphi's 40 Gbit/s modulator driver with Sierra Monolithics' SerDes multiplexer/clock multiplier unit.

As I understand it, Inphi is the sole supplier of DQPSK modulator drivers, while Sierra Monolithics is currently the sole supplier of 40 Gbit/s SerDes. That's because high-speed, high-voltage chips are difficult to make in silicon, so vendors have to resort to other materials systems.

Inphi's DQPSK modulator driver for example, which has to output two streams of 20 Gbit/s at an amplitude of 8 V, is made out of gallium arsenide. (For comparison, networking chips in other roles typically require 1 V.) Meanwhile Sierra Monolithics makes its present generation of chips out of silicon germanium using IBM's 7HP process.

The supply situation will improve over time of course — CoreOptics announced a 40 Gbit/s SerDes chip earlier this year, and AMCC is possible also working on one. But right now the components supply chain isn't complete at 40 Gbit/s, let alone 100 Gbit/s.

In fact, Loi Nguyen, co-founder and vice president of technology for Inphi, told me: "Nobody has a TIA [transimpedance amplifier] for 40 Gbit/s DP-QPSK [dual-polarisation quadrature phase-shift keying]." The TIA sits on the recieve side in the equivalent position to the modulator driver on the transmit side, and amplifies the weak electrical signal coming in from an optical detector before passing it to the SerDes.

DP-QPSK is the modulation format selected by the Optical Internetworking Forum (OIF) for 100 Gbit/s components, which is supposed to hit the market in 2010, and yet it's still not possible to get standard parts for the previous speed incarnation. Clearly components vendors have a lot of work to do.

fibresystems.org is delighted to welcome Jeff Ferry, Director of Communications for Infinera, and a former journalist, as a guest blogger this week. Jeff will be reporting on the OIDA's Photonic Integration Forum, which is the first industry conference dedicated to the commercial development of photonic integration technology. As such it marks an important step forward for this technology area. The conference has been co-organised by OIDA and Infinera.

The conference attracted an impressive 60 experts in photonic integration, says Jeff, filling the room to capacity at the picturesque Monterey Hotel and Spa, perched up against, and partially built out over, Monterey Bay, 100 miles south of San Francisco. So without further ado, over to Jeff...

Tuesday, 7 October, OIDA Photonic Integration Forum, Day One
By Jeff Ferry

Photonic integration

The two most interesting themes of the conference's first day were scalability and power consumption. The debate over scalability turned into a discussion of integration on indium phosphide vs. integration on silicon. The indium phosphide (InP) supporters, led by Infinera, have the benefit of having large numbers of photonic integrated circuits deployed by real customers. According to the chart shown by Infinera co-founder Dave Welch, Infinera has accumulated 101 million hours of PICs running in live networks without a single failure, with each PIC pair integrating 60 devices. That translates to a FIT rate (reliability measure) of 9, which is better than many single lasers and modulators in the market today. "Everything gets better when you integrate, reliability, yield, performance, and costs," said Welch.

Later in the day, Infinera PIC engineer Randy Salvatore provided some insight into how Infinera has achieved its reliability and yields, describing the six stage statistical process control methodology that Infinera borrowed from the silicon industry and applied at its PIC fab. According to Salvatore, when compared to silicon chips and specifically Intel's well-documented history, Infinera has in the last two years made progress equivalent to six years' worth of Intel progress, moving from defect density numbers equivalent to Intel's in 1987 to numbers comparable to Intel in 1993. This, said Salvatore, is the silicon learning curve successfully applied to InP.

Professor John Bowers of University of California at Santa Barbara emerged as the most charismatic advocate of silicon photonics. He showed slides on his UCSB team's progress in several areas, including high-quality photodetectors made from silicon germanium, hybrid lasers made from a combination of III-V materials and silicon, and on the manufacturing side, they've reduced the time required to bond the two materials together from 12 hours to as low as 10 minutes — an important step towards making the technology practical, reliable, and commercial. Bowers said that silicon CMOS technology makes it possible to reduce device size to the point where it becomes possible to get as many as 125,000 die sites (i.e. chips) on an 8 inch wafer. All those developments go towards making silicon photonics PICs more cost-effective than any other material, said Bowers. "Infinera is doing a great job, but the potential for lots more scaling exists," Bowers said. "The platform for VLSI PICs exists. Millions of devices [on a chip] is possible."

Despite the prevailing gloom in the financial sector, vendors exhibiting at the European Conference on Optical Communications (ECOC) were generally upbeat, with one notable exception — Avanex.

Well, a possible reason for the glum demeanour of the employees on its booth just came to light. According to an 8K form filed last week Avanex plans to lay off about 8% of its work force, or 47 employees by the end of this month. The company also plans to close its Melbourne, Florida facility and transfer the product lines, inventory, and fixed assets to its France or China offices. What's more, the executive officers have voluntarily agreed to a 10% reduction in their salaries beginning October 2008.

Avanex seems to be tightening its belt in anticipation of reduced sales in the later part of this year. Although the company posted 5% sequential growth for Q408, which ended on 30 June, it issued guidance for a substantial sequential revenue decline for the following quarter. The company has yet to find a permanent replacement for former CEO Jo Major, who was axed in August, and it's stock has reached an all-time low.

Chaos was the order of the day at the Brussels Eurostar terminal on Thursday, where the reduced service after the fire the previous week left hundreds of travellers queueing to get their tickets validated for one of the few remaining trains. Looking on the bright side, however, if I'd been travelling by plane, I probably wouldn't have got home at all due to an air traffic control failure.

Here are some less stressful memories from the event:

Brussels Expo Hall 10

The Atomium

Beauty parade

Ready for action

FibreSystems prize draw

Mattias Persson & Ted Takeuchi