See You Later, Modulator

DALLAS -- NFOEC 2002 -- Essient Photonics Ltd. today announced a chip that might set the cat among the pigeons in the modulator market -- one day (see Essient Unveils Integrated Modulator).

The Scottish startup says it's come up with a radically different way of translating electronic signals into pulses of light, and vice versa.

According to Essient, this will enable system vendors to pack eight 10-Gbit/s ports onto a line card instead of one, as is currently the case. It'll also slash the cost per 10-Gbit/s port by a factor of four ($10,000 rather than $40,000), and deliver a four-fold reduction in power requirements (250 watts versus 1,000) for a typical subsystem.

Right now, however, these are just claims. All that Essient is showing at the NFOEC show today is a video of its first product -- a combined modulator, amplifier, and detector called the EA-MDA-10G. The proof of the pudding will come when it starts sampling, scheduled for next March. The packaged device will cost $1,395 in volume. Essient will also sell semi-packaged devices to OEM customers.

Commercial shipments are not scheduled until September 2003.

Essient's device is implemented in indium phosphide and includes a waveguide and an electronic device called a resonant tunneling diode. A laser pumps continuous light through the waveguide, and this is converted into pulses by the diode.

This isn't how things work in today's setups, according to Jeremy Chappell, Essient's VP of marketing. Instead of translating digital electronic signals directly into light pulses, the signals need to go through various intermediate steps to amplify and condition them.

That equates to needing lots of transistors -- the addition of which strains the limits of today's semiconductor technologies, according to Cindana A. Turkatte, president and CEO of Xindium Technologies Inc., a startup working in a related field. Essient sidesteps these issues with its technology, according to Chappell.

Chappell maintains that Essient achieves its results without taking a big hit on insertion loss -- a key issue for modulators because high losses force vendors to buy more powerful (and more expensive) lasers. "We're at about eight decibels," says Chappell, who maintains this is average for modulators.

Essient was founded in January 2002 to commercialize technology from Scotland's Glasgow University. The 15-staff startup got a $7 million round of funding from Pond Ventures last March (see Essient Makes an Entrance at OFC).

Competitors? We'll add comments from developers of "traditional" modulators we encounter at NFOEC -- watch for updates.

A couple of stealth-mode startups might also be working on similar developments -- although it's tough to be sure, because neither company will say what it's up to. One of them is Infinera (formerly Zepton Networks -- see More on Infinera (née Zepton)). The other is T-Networks Inc. (see T-Networks Modulates to 40 Gbit/s).

— Peter Heywood, Founding Editor, Light Reading
bw 12/4/2012 | 9:46:09 PM
re: See You Later, Modulator To my knowledge, the best 10G LiNbO with driver of good design consumes less than 2W of power, not the 10W that they try to compare to.. The best way for InP modulator to offer great benefit is to integrate with lasers directly, better yet, integrate with tunable laser. That's the true promise of the technology, becuase you cut out all that PM fiber coupling crap, and loss associated with it..

For array type of modulator to work, the added challenge is packaging all that 10x 10G signal to a small size chip, and not have much cross talk...

For user side, there is no much of a push from user to integrate too many channels into one linecard, due to the inventory cost, etc. with all the possible permutation of wavelength you have to carry on one card... pure nightmare, unless you have tunable lasers, of course..

Phonon-Ex 12/4/2012 | 9:46:08 PM
re: See You Later, Modulator If their claims are true, this may be the kiss of death for 40-Gig technology. I don't think that T-Networks are developing devices at this same level claimed by Essient. T-Networks' modulators are just run-of-the-mill type, with no features that would put them ahead of the competition.


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