Optical components

Agility Unveils Long-Haul Laser

Competition among developers of widely tunable lasers is hotting up, judging by an announcement that Agility Communications Inc. plans to make next Monday (April 2).

The startup says it will unveil “the first packaged prototype of a truly monolithic 10 milliwatt widely tunable laser that can rapidly tune to more than 90 ITU channels” -- a development that marks a couple of significant milestones.

First, this a big boost in power. Agility’s first tunable laser, the Agility 3040, delivers a maximum of 4 milliwatts, which limits its applications to the shorter routes found in metro networks (see Agility Launches First Product).

Boosting the power to 10 milliwatts will enable Agility to start tackling the long-haul market, according to Arlon Martin, Agility’s vice president of marketing. This will bring it into competition with companies such as Iolon Inc. and New Focus Inc. (Nasdaq: NUFO), which are making more expensive, more powerful external cavity lasers.

Agility’s developments also mark an integration milestone. The company has achieved this boost in power by adding an amplifier section to its existing four-section SG-DBR (superstructure grating distributed Bragg reflector) tunable laser (see Tune In! for more on SG-DBRs). The whole thing is developed on the same piece of indium phosphide.

This is much more than a clever demonstration in a lab, according to Martin. Agility has made the laser and amplifier combination and has packaged it on its regular production lines, he says. In other words, it’s relatively close to being a mass-produced commercial product.

Making a complete laser on a single piece of indium phosphide costs a lot less than assembling an external cavity laser (ECL) from three or more chips made elsewhere, the approach taken by Iolon and New Focus, according to Martin.

Iolon, however, points out that there are advantages to its approach. Iolon is in a position to buy best-of-breed chips, while Agility is stuck with whatever it can make itself. “Power isn’t everything,” adds Cindana A. Turkatte, Iolon’s VP of marketing. Other issues such as spectral fidelity are also important and depend on using the best components wherever they're made, she says. She questions whether Agility could achieve the same quality of light transmissions as Iolon with its approach.

"I would argue that [Agility's] process is lower cost, but it's at the expense of performance," says Tim Day, a founder and CTO of New Focus. "A semiconductor optical amplifier will add noise to a laser," he adds, noting that it's a "big penalty to pay" in long-haul networks, where the signal-to-noise ratio is so crucial.

Day also points to other problems with Agility's approach. Adding an amplifier means that the whole assembly needs four different electrical currents to operate. This raises reliability concerns, he says. The ageing mechanisms of lasers needing three currents aren't well understood, so adding a fourth current could make matters worse. ECLs are controlled by a single current, he adds.

Finally, Day says that Agility's design results in tradeoffs among power, light coherence, and tuning range. All three can't be optimized at the same time, as they can with ECLs, he says.

Turkatte suggests that Agility is hyping its ability to penetrate the long-haul laser market because it's having trouble finding customers in the metro market. “We’ve had a lot of their customers come to us,” she says.

Right now, none of these companies are actually shipping commercial products, so the jury's still out on who's got the best tunable laser, and who's blowing smoke. The chances are they'll find different niches.

-- Peter Heywood, international editor, Light Reading http://www.lightreading.com
ownstock 12/4/2012 | 8:38:57 PM
re: Agility Unveils Long-Haul Laser BTW, large part of the added noise should be able to be handled with electronic quieting in the package...Iolon and NF are in big trouble...
ownstock 12/4/2012 | 8:38:53 PM
re: Agility Unveils Long-Haul Laser Better change your pseudonym "opticknowledge", you should consider the following and think a bit...

Optics Letters, Volume 24, Issue 4, 259-261
February 1999

Suppression of classicand quantum radiation pressure noise by electro-optic feedback
Ben C. Buchler, Malcolm B. Gray, Daniel A. Shaddock, Timothy C. Ralph, David E. McClelland


We present theoretical results that demonstrate a new technique that can be used to improve the sensitivity of thermal noise measurements:intracavity intensity stabilization. It is demonstrated that electro-optic feedback can be used to reduce intracavity intensity fluctuations, and the consequent radiation pressure fluctuations, by a factor of 2 below the quantum-noise limit. We show that this reduction is achievable in the presence of large classic intensity fluctuations in the incident laser beam. The benefits of this scheme are a consequence of the sub-Poissonian intensity statistics of the field inside a feedback loop and the quantum nondemolition nature of radiation pressure noise as a readout system for the intracavity intensity fluctuations. [Optical Society of America ]

I reiterate: great product!

OpticKnowledge 12/4/2012 | 8:38:53 PM
re: Agility Unveils Long-Haul Laser I don't think so "ownstock". That's a fairly large assumption "ownstock". The noise issue isn't that easy to eliminate. The technique of using an external cavity is more reliable from a lowered noise level standpoint.

OpticKnowledge 12/4/2012 | 8:38:51 PM
re: Agility Unveils Long-Haul Laser I'm curious to know "ownstock", the article you present, is it a theory that can be undisputed or is it based on a couple of "theoretical results" (as stated from the article)? If the answer is that the reduction in noise is only based on a couple of "theoretical results" then I believe that I don't need to change my username and I think you may want to ponder your own question of whether or not you should change your own pseudonym, "ownstock". I only wonder what stock you really own, possibly a public company that is aligning itself with Agility? Hmmmm.

The article sounds great but if it's only theoretical results, shouldn't you reserve judgment until more experiments and tests have been thoroughly completed?

Knowing this now, should I be exclaiming: great product!
OpticalValueLine 12/4/2012 | 8:38:50 PM
re: Agility Unveils Long-Haul Laser We need to see the real products. I did not see Agility's live run in the OFC. Nortel and other guys did (of course not New Focus and iolon either). In this market, everyone with cool head knows you hardly survive without cool revenue coming. In the laser industry (not passive), prototype is really really far from revenue, needless to say there is (I bet) no real network guy seriously talking tunable lasers. Frankly, our indurstry still is filled with a lot of bulbs. But I am looking forward to seeing their laser anyway.
ownstock 12/4/2012 | 8:38:38 PM
re: Agility Unveils Long-Haul Laser Have you ever heard of squeezed states of light? A little reading will enlighten you (pun intended). All Agility has to do is incorporate the MZ modulator (which is what the thing is designed to feed) into their product, and an analog negative feedback loop, and they are done. As to my position wrt Agility, I currently own zero stock, but may invest soon (as the optical component market regains sanity) based (in part) on this announcement.
OpticKnowledge 12/4/2012 | 8:38:28 PM
re: Agility Unveils Long-Haul Laser Ownstock,
Do you know if Agility has been successful at incorporating a MZ modulator yet?

ownstock 12/4/2012 | 8:38:05 PM
re: Agility Unveils Long-Haul Laser Not at the package-level, but this could be a "card-level" product...someone elses MZ for example...at least for the first couple of years or so...
^Eagle^ 12/4/2012 | 8:37:48 PM
re: Agility Unveils Long-Haul Laser The issue is what is an acceptable noise level for the application. I believe that most long haul applications will be addressed if RIN is less than -145 and SMSR is less than -40. Linewidth is also key. Long haul would like linewidths as narrow as possible. But most applications work fine with line widths narrower than 10mhz. Some use as narrow as 3-5mhz...depending on platform.

It is useless to speculate on theoretical noise issues. If Agility has figured out how to make a device that meets the needs of the industry...all these theoretical jabs will go away. Lets wait and see what kind of performance they actually achieve instead of speculating on the theoretical problems associated with their device. It could easily be argued that there are equal theoretical problems with the external cavity approach...

Both approaches have the theoretical ability to come up with a solution...both have serious hurdles to overcome.

Agility does indeed have to control multiple sections in thier semiconductor. One would assume that the VC's would not be so anxious to buy into Agility if they did not have this fundamental issue worked out....especially in this current stock market! Agility has shipped devices since Oct. that control 4 section SG-DBR's. Not too much of a stretch to believe that they can control a 5 section device that has an added SOA. Agility also has to prove they can pass reliability tests...but fairly low risk as these DBR lasers have been proven to be reliable by many companies.

Iolon/NF have a cost issue, challenges ramping to high volumes with the mechanical approach, unanswered reliability questions, and SLOW tuning speeds. They also cannot integrate other functions on the chip like Agility can....so adding functions is an Agility advantage. Iolon and NF can address the sparing market...but the economics there are much tougher...the OEM's don't want to pay a big premium for sparing or inventory reduction...so Iolon and NF will be squeezed by cost/pricing pressures to close deals. And the OEM's that could use this approach virtually all have their own in house designs for slow tuning, narrowly tunable lasers for sparing and inventory reduction. So Iolon and NF are pushed into the most difficult application in the market. IT is very hard to even prove in tunables economically for sparing as the savings numbers are so nebulous.

The real value for tunables is in dynamic network applications....be it Long haul or metro...OADM, OXC, wavelength conversion, routing, etc. Key will be dynamic network designs. This area requires features where Agility has a much stronger position than the external cavity vendors. Fast tuning, very reliable design, high volume manufacturing, cost advantages. Etc. Also in metro applications where integration of other features into the chip...like modulators...this is key to driving down cost and driving up density in the metro space...and should give Agility an advantage.

Agility and the External cavity guys all have to prove themselves now with products that ship. And then we will see beyond theoretical speculation.


ownstock 12/4/2012 | 8:37:39 PM
re: Agility Unveils Long-Haul Laser Spoken like a person who knows technology and business too! Now if we could only have LR call you before they submit another negative spin article on one of the companies they (or their investors) are not invested in!

...not holding my breath...

PS: I assume you mean MHz, not mHz... :-)
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