Regular Light Bulbs Made Super-Efficient with Ultra-Fast Laser

The old light bulb might get new life.

http://www.rochester.edu/news/show.php?id=3385

I guess all those sci-fi movies were right; the future does revolve around lasers!

Well, that's just fine and dandy, ain't it! Just when they have all vanished from our stores here.

Just think of the logistics. Using a multi milion dollar laser to make a lowly lightbulb more efficient. Does this thing work on only one bulb at a time or could it do a whole batch at once? 'seems like a really expensive way to do it.
It's still really cool though.

This is a process for the bulb factory, you don't need a laser in each luminaire

A 40% reduction in power is probably not enough to make them compete with CFLs but it is interesting.
I wonder what this does to filament life.

I know that it would be done in a factory making these things. I was just curious about the logistics of a factory doing this. Obviously, if you had to do it one bulb at a time, a factory could not use this technique.

Greg I wondered about that too. The life of a tungsten filament [at design temperature 3100º-5400ºF] is a factor of surface damage to the filament, at a heat approaching the fusion point of tungsten [6192ºF] and by cyling on and off. Minute cracks and 'hot spots' appear, which slowly enlarge and lead to failure, buffered by the choice of inert gas fill, argon, nitrogen, halogens. If this 'laser surface' treatment is degraded by the heat in less than the normal bulb life, the whole idea will be useless.

Ian, the pulse is so short that it wouldn't really slow down the line if they shot each bulb one at a time as they go by. I assume they would cost a little more but if I was in the incandescent bulb business I would be willing to do a lot to save my business.

It seems that it takes more than one shot with the laser. The article stated that the treated "spot" was brighter. There is no report on the size of the spot, could be anywhere from 1/3 of the filiment (meeting the largest size I could call a spot) to the size of the pointed end on a pin or smaller depending on what they were using to observe the spot.

Very good point. Lasers, at the power levels they are working with, have beam diameters of just a few microns. So, I would imagine, the affected area of the filament would be very small indeed.

I don't know enough about incandescent light bulb manufacturing to know how this would work but I do understand if they don't get a plan soon to ramp up efficiency they will go the way of oil lamps and buggie whips.

I don't know about the US in general, but incandescent bulbs are being phased out in the EU. As of about 2 months ago the 75W and above bulbs have all but disappeared from the supermarchés here. I fitted all CFLs where posible in our remodel [at over $400 ouch!] and can say I'm quite pleased with the light's color rendition, if not the price!

http://redgreenandblue.org/2008/10/11/eu-bans-incandescent-light-bulbs/

Guess I better get some more 15S14s while they are still around. That is my favorite bulb for accent lighting. I have about 18 of them around the pool and back yard. Most are on a dimmer so they don't really use the full 15 watts.

We buy blue 11W S14's in backstage worklights. They last a long time, and are pretty cheap... A case of 20 is $19 from Sival.

I'm slowly switching over to CFL's as the old incandescent burn out, which is surprisingly rare in my tiny duplex.

I get the 130w lamps and I nave never had one burn out. You get a surprising amount of light out of these in a frosted globe luminaire but most of them are in H101 type lamp holders about 13' above the pool. It gives us enough light for adults. When the kids are here I turn on the PAR38s so we can keep a good eye on them.

I always specified the 130V lamps and nobody can see the miniscule difference in light output; but they sure seem to last forever.
I was once told that the traffic lights (before LED) used 130V rough service lamps so the crews wouldn't constantly be out with the truck replacing them.

I chuckle when it comes to lamp life, but first I have been extremely dissapointed in the color renditioning of the TCP brand CFL (I would rate it just better than an HPS - High pressure sodium) where as the GE and Sylvania styles I have are very acceptable.

The light output initially and over time as judged by the human eye (mine) is less than advertised. If I want the equivilent of 60W incandescent, I must go for the more expensive 18W CFL not the 13W.

Getting back to life, I have replaced over the past several years (in my home) every TCP brand CFL due to burn out (at least I think I have, and it was a total of 8 minimum, average age at death 12 months maximum, the paragraph below explains why three lasted about 6 months), and 2 of the 6 GE CFL (bought about 2 years ago). During the entire time I have replaced only 4 incandescents of which the majority of the house is and most are the original lamps in the fixtures at 14 years old.

That being said, I have one of the GE's in a fixture that blew incandescents, one per every 9 months, without problem. And I have one Sylvania CFL that I receieved 15 years ago when I first became aware of them, that is still going. From my experience it appears that heat takes these things out quite nicely and that the more open a fixture is, the longer they last (you should never mix these with incandescents in an enclosed fixture (duh! so I learned form my effort of trying to keep the light level up and improve color renditioning in 3 fixtures)).

My wifes biggest complaint with the GE 13W CFL's is the amount of light is down. After a couple of minute of warmup they come close, and she is getting used to them, but not in the bathroom thus the higher wattage. Again that old Sylvania is right there at full light within a few seconds, gotta love that blinking at turn on due to the built-in ballast type.

My favorite use for the CFL's... My drop light. For those who may be unfamiliar with they term, a drop light is a portable hand held lamp and guard used for working in tight places like on your car.

This was simply the laser they were using in the lab- I'm sure they were using the laser that was available. Now that they know this impacts brightness, they can toss some seed money to a few grad students to do some more intensive studies on what power levels work best, if wavelength matters, etc. From the sounds of it, this is affecting only the very very top surface of the surface, maybe a few atoms down- enough to change the wavelength of light emitted by the filament, but not actually damage the filament.

Commercial installations would undoubtedly use a more powerful laser on an assembly line, blasting away at the bulbs as they pass by at 50mph. We have cheap solid-state lasers powerful enough to cut 3/8" thick place steel to micron tolerances and blast artillery shells from the sky, so this isn't anything all that difficult. If it means improving incandescent bulbs in applications that still use them, that's great.

Only doing part of the filament was also most likely for comparison purposes; the untreated part of the filament was the "control".

Regarding CFLs, you should save your receipt. The current GE residential lineup are guaranteed for 5 years, and I remember the old "Lights of America" ones that were being sold a few years ago were guaranteed for 7 years. I've had to take a few of the old LOA ones back earlier in their model life with no problems; imagine the look you would get when trying to exchange an incandescent.

IIRC, the traffic light bulbs were rated at 10,000 hours... I knew a guy who worked for the public works department, and had brought a few home for use in his house. Output seemed a little less than a standard 60W, but not by much.

In fact, here's a 60W variety that is advertised at 16,000 hours: http://www.bulborama.com/store/cart.php?m=product_detail&p=698

If all the laser did was to make the filament a little thinner at that spot, it will get hotter at that spot (as the same current is going thru the entire filament). As the spot is a patch of higher resistance per unit length than the rest of the filament, and it may burn out at the bright spot. But doing the entire filament would just give you a lower wattage bulb, if the entire filament has the higher resistance per unit length.

So be careful before you run out and invest in this new technology...