Optical components

Terapulse Aims to Pummel PMD

At the upcoming OFC Conference, many companies will make a big marketing push in order to keep all eyes on them. Others, however, will quietly chat up potential customers, ducking the limelight at every turn.

Optical subsystems maker Terapulse will be among the quieter companies making the trek to Atlanta in March. The company's executives, including president Steve Wein, will be around the show and conducting meetings at a nearby hotel.

Clues indicate that Terapulse is looking to help carriers build faster networks by tackling one of the problems that comes with faster optical transmissions systems: polarization mode dispersion. PMD occurs when optical pulses travel down a fiber at different speeds and arrive at different times. This causes a smearing of the optical signal received at the other end of a transmission, which results in lost data, botched phone calls, etc.

Several companies are already tackling PMD and other high-speed signal degradation problems. These include the subsystems vendor BTI Photonics Inc. and the components vendor LaserComm Inc. (see Pushing the Limits on Optical Monitoring and Layoffs Level LaserComm). Yafo Networks tried, but The Reaper got them earlier this year (see Headcount: Time to Punt?).

"Initially our plans were to launch at OFC," says director of marketing Peter Hunt. The company has since decided to hold off for a few months, but it is attending the show anyway. "It's a good way for us to touch base with our potential customers."

Terapulse was founded in January 2001 and has raised about $20 million to date. It closed a Series A round of $10 million in January 2001 and a Series B round of $10 million in December 2002. Matrix Partners and North Bridge Venture Partners invested in both rounds, and Flagship Ventures joined in the B round.

James Targove founded Terapulse and now serves as its chief technology officer. Before Terapulse, Targove was a consultant for Optical Research Associates (ORA), where he aided several companies in designing and manufacturing DWDM filters and optical components. Before ORA, Targove spent four years at Itek Optical Systems, a company that built optical sensors and multichannel active optical compensation systems for aerospace businesses.

Though Targrove's background offers some hint, Terapulse won't say specifically what it's working on. Hunt generically describes the company as a seller of optical subsystems to equipment vendors and carriers in the high-speed transmission market. "That's not limited to the long-haul market."

The whole of Terapulse's technology is still a mystery. But one part of it was recently uncovered in a thickly-worded patent application. Judging solely by those documents, Terapulse has invented a way of "compensating for PMD in an optical transmission system without perturbing the laser source."

The gadget likely provides for a way of measuring PMD that avoids interrupting data transmission, while at the same time allowing for fast compensation of PMD effects.

Terapulse's invention compensates for PMD by transferring a sufficient fraction of the light signal in an optical transmission system into a single PSP (principal state of polarization) of the system, according to the patent paperwork. (PSPs are one of two main modes that govern how light is spread through an optical fiber).

Because of this transference, each light pulse in a data stream is kept from mixing with adjacent light pulses. The end result, presumably, is a transmission system that sends lots of data, very quickly, with hardly any loss or corruption.

Will the thirty-person startup say much else at OFC? Perhaps to a potential customer. "They're a conservative group, says Stan Reiss, the Matrix principal who sits on Terapulse's board. "Wein is probably the shrewdest guy in our portfolio."

— Phil Harvey, Senior Editor, Light Reading

Dr.Q 12/5/2012 | 12:31:36 AM
re: Terapulse Aims to Pummel PMD Remember Yafo Networks? (How quickly we forget.)

They tried to build a business around PMD compensation, saying 40 Gig was just around the corner.


kokoro 12/5/2012 | 12:31:36 AM
re: Terapulse Aims to Pummel PMD Does anyone know what BTI Photonics Inc. really does against PMD???

Mister Light Wave 12/5/2012 | 12:31:24 AM
re: Terapulse Aims to Pummel PMD Hello,

What is your diferentiator from your PMD buddies at http://www.santelnetworks.com/ ??

Mister Light Wave
Mister Light Wave 12/5/2012 | 12:31:24 AM
re: Terapulse Aims to Pummel PMD Wow !

Another VC firm is duped in 2003, you think they would have learned by now. This Principle State of Polarization mumbo jumbo is flat out crap. PMD is cause by random fluctations in the birefringence of the fiber from micro bends, temp ocillations, etc. Any injected "PSP" will mix remix and mix again into a jumbled mess.

These VCs should watch the movie catch me if you can they may learn how to spot an imposter.

I have an invention call FMO which transmits 40G 50,000 km. I will see if I can hoodwink some VCs out of 20 or 30 million.

Mister Light Wave

PS: FMO is "F&*^%$# Magic Optics"
Demander 12/5/2012 | 12:17:48 AM
re: Terapulse Aims to Pummel PMD At any instant in time the fiber has a PSP no matter how 'jumbled' the stresses are; it just changes on a ms time scale. Evidently Terapulse thinks they can sense the PSP and exploit it. It seems to me that there could be a different PSP for each wavelength channel. That would make things tough.

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