Optical components

The Shape of Things to Come

One of the biggest problems with designing complex optical components is what shape to make them. The usual method involves trial and error -- picking a structure, then simulating how light will flow through it. But it would be considerably more useful to have software that could perform the reverse calculation -- starting from an optical function and then working out the precise shape needed to achieve it.

That's the challenge that Salt Lake City startup Silicon Optics Inc. claims to have successfully met.

The startup recently completed development of a package of software tools for designing optical components. It's officially out of stealth mode -- although it isn't making a lot of noise about it -- and plans to seek institutional venture funding and expand to 40 people in the near future.

Silicon Optics isn't planning to sell its software, however. On the contrary, it's going to keep hold of it and use it to design "photonic crystals" -- microscopically patterned materials that might be used to produce the true optical equivalent of the electronic IC (see The Hole Thing).

So who's behind this breakthrough? The credit goes to David Dobson, a former professor at Texas A&M University. In 2000, a year after starting the company, he won a prestigious mathematical prize, called the Felix Klein Prize, for his work on computing shapes from optical functions -- known as "the inverse problem" in mathematical circles.

But it was his brother Kurt who spotted the business opportunity. "Four years ago, we discussed photonic bandgap work," Kurt says. "And it seemed to me that it would be possible in the next four to five years to make a commercially viable device."

So Kurt, a former VP of corporate advanced development at 3Com Corp. (Nasdaq: COMS) and US Robotics, provided the seed money for Silicon Optics to get started. Kurt is now the startup's CEO. David is its CTO.

(As an aside, the brothers have also founded another startup together, called Spectrum5 Racing, which offers software for modeling racing car engines. This subject is obviously close to the brothers' heart, as Kurt had to postpone a call with Light Reading because he had hurt his hand in a racing accident. What is it with optical executives and racing cars? (See Cisco's Russo Resigns and Redback's Blair off to the Races.)

Kurt Dobson reckons Silicon Optics is ahead of the competition thanks to its software, although he realizes the road ahead is still a long one (with a hairpin or two). The company doesn't expect to have a commercial product for the next two years.

Direct competitors include Canada's Galian Photonics Inc., Luxtera Inc. in the U.S., and Mesophotonics Ltd. in the U.K. Galian has said it should have prototypes in customer hands next year, putting it in the lead in terms of its product schedule (see Galian Sets Sail). The other companies haven't said a lot about their plans to date.

"They're very smart guys [at our competitors]," says Dobson. "But they are just guessing at what geometries might be needed to accomplish a particular function, and then running it through a simulator. But they'll never guess the shape, because its completely non-intuitive."

Most people making photonic crystals are patterning arrays of square rods or round holes. "That's not the correct shape," Dobson contends. (Examples of structures designed using Silicon Optics software are shown on the startup's Website at www.siliconoptics.com/Publications.htm.)

Furthermore, Dobson points out that traditional methods for simulating photonic crystals don't take into account any imperfections in the manufacturing process, such as misalignment and surface roughness. Since the optical properties of a photonic crystal depend so strongly on its shape, those imperfections can kill the performance of a device. Silicon Optics' software, he claims, can create an optimal design that takes these imperfections into account.

The only strange thing about Silicon Optics is that, by its own admission, other experts in photonic crystals don't seem to have cottoned onto the apparent significance of what it is doing.

One possible explanation is that David Dobson and his colleagues move in mathematical circles, whereas most other researchers in the subject have physics backgrounds. And he has managed to keep his company and its work fairly low-key so far.

Light Reading tried to contact some experts in the field of photonic crystals, but only one responded. "It certainly sounds like a powerful program," says Professor Gareth Parry, who directs photonic crystal research at London's Imperial College and is also a director of U.K. startup Kamelian Ltd.

— Pauline Rigby, Senior Editor, Light Reading

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