Optical components

Polychromix Claims MEMS Advance

Startup Polychromix Inc. emerged from stealth mode yesterday to tell the world it's developing dynamic optical components that will help carriers provision and manage their networks remotely (see Polychromix Reveals Plan).

Despite the fact that it only began operations last summer, the startup already has prototypes in its labs, and it's currently ironing out the details of customer testing deals.

The company hit the ground running because it's building on technology that had already been in development for five years at Massachusetts Institute of Technology (MIT), Sandia National Laboratories, and Honeywell International Inc. (NYSE: HON), under a contract with the U.S. Department of Defense. The project's aim was to create new kinds of chemical sensors using micro-electro-mechanical systems (MEMS).

Polychromix was formed when two of the project leaders, Stephen Senturia from MIT and Michael Butler from Sandia, negotiated exclusive licenses to develop the technology for telecom applications. All they needed then was some cash. Seed Capital Partners and Vanguard Ventures stepped up to lead a funding round of $7 million last summer.

"It's our job now to convert from a technology-push company to a customer-push company," says Mouli Ramani, the startup's VP of marketing.

Polychromix calls its technology "programmable micro-diffraction gratings." It's based on something that looks like a miniature piano keyboard, says Ramani. Different patterns of keys on the keyboard can be depressed, so the reflections from the keys form interference patterns, which effectively turn the reflected light beams in different directions.

Hang on a minute. Isn't that the same as the technology being developed by LightConnect Inc. and Silicon Light Machines, two companies that were founded by David Bloom from Stanford University? (See LightConnect Comes Into Bloom.)

Ramani agrees that it is similar, but "as they say, the devil is in the details, and we have some details that we think will make our product very attractive to carriers."

The structural details of the MEMS are quite different, he adds. "When we move our piano keys, they remain flat. That provides better control of the optical phase, which translates into better performance." The implication, of course, is that SLM and LightConnect have curved surfaces in their devices.

As a result, Polychromix claims its component has better polarization-dependent loss, better dynamic range, and lower power consumption than its competitors. Dynamic range is an important parameter because it describes how well the device can block a single wavelength. It's tough to check out these claims, however, since Polychromix says it is too early to give exact specifications.

Peter Clark, LightConnect's president and CEO, acknowledges that the ribbons in his company's device bend but says the bend is "negligible" -- a matter of a couple of microns over a distance of a millimeter. "The devil's not in the details, the devil's in the performance," he says.

All should become clear later this summer, when the startup introduces its first product. Called the "Dynamic Channel Orchestrator," it will perform channel blocking, attenuation on a per channel basis, and power monitoring in a single device, according to Ramani.

By combining two devices, it is possible to make a reconfigurable optical add/drop multiplexer that will fit onto a single line card, he boasts. A splitter at the input of the ROADM sends half the light to one DCO, and half to the other. One of the DCOs blocks the through wavelengths, while the other blocks the drop wavelengths.

If Polychromix can make it work, this could prove to be winner, since it sounds like a more compact version of an architecture that is already growing in popularity for optical add/drops (see Dynamic Gain Equalizers Diversify).

— Pauline Rigby, Senior Editor, Light Reading

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