x
Optical/IP

LMG Gets a Boost From Boeing

Light Management Group Inc. (OTC-BB: LMGR) announced today that The Boeing Company has agreed to evaluate LMG's acousto-optical switch for use in its commercial, space, and military products (see Boeing to Assess LMG Switch).

This brings the total number of companies testing LMG's switch to four. The others are France Telecom SA, Empyrean Communications Inc. (OTC-BB: EPYN), and FiberWired Burlington

All this suggests that the company isn't as flakey as it first appeared (see Acousto-Optical Switches: A Sound Idea).

In fact, it suggests that acousto-optics could be a serious alternative to MEMS (micro-electro-mechanical systems), the technology with the tiny tilting mirrors being used in most all-optical switch developments at the moment. A big reason for LMG's perceived progress is networking -- not in the optical sense, but in the person-to-person sense. FiberWired Burlington, for example, is a provider of fiber-optic connections to businesses in Ontario, where LMG has its head office. FiberWired came calling one day, to offer fiber-to-the-business to LMG, and the two companies spotted that they might help each other, according to Don Iwacha, LMG's president.

Iwacha also says that LMG's potentially most important deal -- with France Telecom -- was made through personal contacts.

LMG's acousto-optical switch works by using sound waves in a crystal to deflect a beam of light. Simply put, the peaks and troughs of a sound wave create a grating, one that can be turned on and off or tuned by altering the sound wave's frequency. The amount of deflection is varied by changing the frequency of the sound.

Acousto-optic technology has two key advantages over MEMS. First, there are no moving parts -- and thus nothing to jam, break, or wear out. And second, its switching speed -- a few microseconds -- is about 1000 times faster than MEMS (see Optical Switching Fabric).

In a recent press announcement, LMG claimed its switch has performed more than one trillion switching cycles over two years without any need for maintenance. "This tremendous durability eclipses the traditional micro-electrical-mechanical systems (MEMS) fiber optic technology, which requires maintenance at roughly every millionth cycle," it says.

At the end of 2000, LMG demonstrated a switch with a single input and up to 1,024 output positions (see LMGR Debuts Acousto-Optic Switch). In the switch, all the possible output positions lie in a straight line, so they can be accessed by a single deflector. Since then, the company has extended the idea to four inputs and 32 possible outputs for each input, essentially by placing four single-input switches side by side.

Most recently, LMGR has developed a switch where the beams can be deflected in both the x and y directions. This is done by using two crystals that carry sound waves at right angles to each other. One of the fringe benefits of doing things this way is that the resulting device has no polarization sensitivity. The device has eight inputs and 64 possible outputs.

Of course, the big question is: Will any of the trials turn into contracts? Right now, its too early to say, says Iwacha.

— Pauline Rigby, Senior Editor, Light Reading, http://www.lightreading.com

Page 1 / 2   >   >>
thorny 12/4/2012 | 8:19:04 PM
re: LMG Gets a Boost From Boeing An agreement with Boeing is nothing to sneeze at.

Also glad to see that Ms. Rigby was finally able to admit her bias against LMG in previous articles: "All this suggests that the company isn't as flakey as it first appeared..."!

Nice objective reporting, Ms. Rigby.

Greg
ownstock 12/4/2012 | 8:19:00 PM
re: LMG Gets a Boost From Boeing Acousto Optical switching is a total yawn...too big, too expensive, low optical efficiency...OK, delete this one too...so much for LR being a news source...
nanovision 12/4/2012 | 8:18:49 PM
re: LMG Gets a Boost From Boeing Ownstock(Peta...)

Hellow?
nanovision 12/4/2012 | 8:18:49 PM
re: LMG Gets a Boost From Boeing http://content.communities.msn...
Petabit 12/4/2012 | 8:18:45 PM
re: LMG Gets a Boost From Boeing You rang?

Thanks to whoever posted the links the datasheets. I picked up some copies at OFC. LMGR still don't seem to have got the hang of writing specs using telecoms language, so let's translate:

8x64 switch
Insertion loss: no mentioned directly, but the difraction efficiency is quoted at 40% at 1310nm. So that's 4 dB loss for the switch, plus at least another 2-3 dB for the collimating optics. My guess 6-7 dB total loss.

Crosstalk: 20 dB
PDL: None. No device has zero PDL, it can be <0.1 dB (etc). If you mean <0.1 dB, say it, otherwise I don't believe you that the PDL is zero.
Switching speed: 0.09 us

So let's compare that to a MEMS 8x8 (since almost all the optical switch requirements in telecoms need symmetric switches). Say a Telecordia qualified one.
Insertion loss: 4 dB
Crosstalk: 40 dB
PDL: <0.2 dB
Speed: 100 us

The insertion loss is the kicker. Every fraction of dB counts, and 6-7 dB is much higher than the competing technologies. I don't need an 8x64 switch - I need either an 8x8 or a 64x64.

The crosstalk doesn't help either, you need at least 30 dB isolation to stop the data corrupting other channels, preferably a lot more.

So Mr LMGR, the other specs that I would like to see are:

1. Switching bandwidth. I know that you can switch channels over 300 nm, but how many WDM channels can you switch at once. You yourself decribe the 'diffraction efficiency', so how wide is the diffraction bandwidth? Normally AOTFs have a relatively narrow operating regime that comes from the geometry of the grating - 30-40 nm is common.

2. Power flatness. 6-7 dB insertion loss is not too bad, but how does it change over the channels? I need 0.2 dB flatness across the whole C and L band.

3. Aging. How does the inserion loss change over time? Do you need to keep re-steering the beam to correct for drift?

Thank you.

P.
ownstock 12/4/2012 | 8:18:41 PM
re: LMG Gets a Boost From Boeing AO also has the inherent problem of being sensitive to wavelength...the opposite of MEMs. Really great technology now that everyone is going to DWDM. As to diffraction efficiency, that 40% is with a single beam...hardly realistic. With multiple beams, it has to drop considerably or suffer crosstalk...

People, this is a laser light show company for Gods sake! Get real! Spin died last year!

-Own
nanovision 12/4/2012 | 8:18:37 PM
re: LMG Gets a Boost From Boeing Skeptic right from the beginning, eh?

Did't you say last year that they couldn't and shouldn't do it? They now have 1x1024 AOD switch which you ridiculed(Who needs it?). Pretty soon they will come up with 8x64 AOD switch which will allow all input ports to operate simultaneously and what are you going to say?

Wasn't it the Russians who sent the first satellite, Sputnik, into the orbit around the earth? They are now going to take FO communications into aerospace with Boing and you maybe left behind with your beloved,outdated broken MEMS switch and wonder why?

BTW, MEMS switch speed is milliseconds not microseconds.
ownstock 12/4/2012 | 8:18:35 PM
re: LMG Gets a Boost From Boeing What I did say was this stuff was done many many years ago...today it is a technology is search of a problem...and some suckers to invest in what is just a holdover seventies laser light show company.

Speaking of the seventies, and trying to say something positive, it was really cool watching Ar/Kr ion laser light shows in the local planetarium a few hours after eating Magic Mushrooms!

BTW, most of that was bits of mirrors on old HiFi speakers we stole from Dad's worn out home made (remember Heathkit?) stereo. Come to think of it, that was the precursor of MEMs. Even then it was better than AO, how ironic...but I digress...

These days, it would take a large dose of Ecstacy to get me to take AO seriously...and I say that having written a few papers on the topic...

Boeing is obviously suffering from too much time at high altitude with no Oxygen mask...

As we say: Good luck to you in your investments (or your career)...

-Own
Lighteating 12/4/2012 | 8:18:32 PM
re: LMG Gets a Boost From Boeing Do you have the titles of some of these papers you wrote while on Ecstacy? Are they, you, still in the public domain?
ownstock 12/4/2012 | 8:18:16 PM
re: LMG Gets a Boost From Boeing "Improved Optical Efficiency of AO Switches Under the Influence of Illegal Substances" Ownstock et.al., Journal of Irreproducible Results, Volume 12, Number 3, 1975

Abstract: Use of Magic Mushrooms by the experimenter appears to enhance (transiently) the optical efficiency of large aperture Bragg cells. The effect is especially pronounced within four hours of starting the experimental protocol. Crosstalk was not measured, but was ignored completely, as it was difficult to focus on the rather blurry (but very colorful) output beams. No RF source was needed, as the "buzz" from the experimenter was sufficient to generate slow shear waves in the 001 axis.

"Unique Two Dimensional AO Optical Switches" Ownstock et.al., Journal of Irreproducible Results, Volume 14, Number 2, 1978

Abstract: By crossing ones eyes, and staring intently, it is possible to see "depth" in otherwise shallow results. This effect is enhanced with the use of illegal substances. (op. cit.)
Page 1 / 2   >   >>
HOME
Sign In
SEARCH
CLOSE
MORE
CLOSE