Gemfire Comes Out Blazing

Integrated optics startup announces first products, heavyweight backers

March 5, 2001

4 Min Read
Gemfire Comes Out Blazing

In components, the name of the game is integration, and today's announcements from Gemfire Corp. indicate that the company could become a significant player in this space.

Gemfire unveiled its first two products -- an eight-port laser array for pumping optical amplifiers, and an eight-port variable optical attenuator (VOA) array (see Gemfire Announces Products). It claims that both products will allow systems designers to increase functionality while cutting the cost per function in half.

In a separate release, Gemfire revealed that it's bagged a $63 million third round of funding, from an impressive list of backers (see Gemfire Raises $63 Million). On the VC side, the money came from Hook Partners, Kleiner Perkins Caufield & Byers, Mohr Davidow Ventures, and Spring Creek Partners. Gemfire also managed to gain backing from no less than five vendors: Cisco Systems Inc. (Nasdaq: CSCO), Corning Inc. (NYSE: GLW), Finisar Corp. (Nasdaq: FNSR), Intel Capital, and TriQuint Semiconductor Inc. (Nasdaq: TQNT).

What's got them all so fired up? According to Rick Tompane, Gemfire's CEO, it's because Gemfire is one of the few manufacturers that's able to integrate both active and passive functions on an optical chip. Plenty of other vendors intend to do this -- but it's easier said than done.

Gemfire jumps straight on active devices with its pump laser array, which it sees as a key product for cost-sensitive metro networks. "Early metro networks stayed away from optical amplifiers, but system designers struggled to achieve low-loss noise figures," says Tompane. "Now they realize that if they add a little bit of gain it gives them a much easier way to get system margin."

That means, of course, that the amplifier needs to be cheap. In amplifiers, the expensive part is the thermal stabilization and control for the pump lasers, which is needed because laser wavelength shifts with temperature, says Tompane. Gemfire's answer: Put multiple laser bars onto the same platform -- a piece of silicon -- so they can share the thermal stabilization costs. Each laser is controlled individually.

Gemfire's other product, the VOA array, is a different beast altogether. It's based on the thermo-optic effect in a polymer. Heat the polymer and its refractive index changes. An optical circuit of some kind (not an interferometer, which is bulky, says Tompane) is used to translate that index change into an optical intensity change. There's more change for less heat in a polymer than in many other materials, so the resulting device consumes very little power -- 8 to 10 milliwatts maximum per port, which is about 10 times lower than silica-based devices, Tompane claims.

The flip side of being highly sensitive to temperature is that such a device might need very careful temperature stabilization. But Tompane says Gemfire's avoided this problem. It's achieved a first by designing an athermal thermo-optic-based VOA (one without a cooler). That helps reduce costs further.

Gemfire says it will have product samples available shortly after the upcoming Optical Fiber Communications show, and move rapidly from there. In fact, it sees customer acceptance of a new technology as the main hurdle to getting out into the marketplace, particularly with regard to the polymer. "Polymers have had a spotted history," says Tompane. "It's not enough to say it's Telcordia rated. People will still want to test it in their own labs."

The fact that Gemfire has expertise in a lot of different materials -- it claims it can work in ceramics, silica, and gallium arsenide, as well as silicon and polymer -- marks out a new trend in integrated optics. Rather than try to find one material that can do everything, startups are realizing that a better solution, at least for the current level of integration, is to pick the most suitable material for the job in hand.

It's also worth noting that one of Gemfire's founders was Dr. David Deacon, who holds five key patents relating to indium phosphide, one of the few materials that can be used to make both active and passive optical devices. Deacon has now founded another startup, Sparkolor Corp. (see Sparkolor Plays Catch Up).

At this stage it's hard to say who Gemfire's competitors will be. Both IPG Photonics Corp. and Southampton Photonics Inc. say they're doing multiport pumps and amplifiers, though the underlying technologies are rather different (see IPG Hides Its Light Under a Bushel and Startup Claims First Multi-Port Amplifier). Bookham Technology PLC (Nasdaq: BKHM; London: BHM) is one of the most advanced companies putting active devices on a chip (see Bookham: Is the Tide Turning?), while Telephotonics Inc. could be a challenger to Gemfire's polymer-based products (see Startup Creates Component Cocktail). As Gemfire and other startups release other new products, this scene will change rapidly.

— Pauline Rigby, senior editor, Light Reading

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