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June 3, 2009 10:44 AM PDT

Can lasers save the incandescent lightbulb?

by Candace Lombardi

A new breakthrough may change the attitude that the incandescent lightbulb has had its day.

Compact fluorescent lightbulbs (CFLs) have unquestionably gained popularity for their energy efficiency when compared to the traditional incandescent bulb. Millions of people around the world have been encouraged by politicians, governments, energy utilities, and even lightbulb companies themselves to phase out traditional incandescent bulbs in favor of CFLs (or even LEDs) to save electricity in the home.

But now researchers at the University of Rochester in New York say they've found a way to make an incandescent lightbulb more efficient.

Chunlei Guo, associate professor of optics at the University of Rochester.

(Credit: University of Rochester)

A group led by Chunlei Guo, associate professor of optics at the University of Rochester, has been testing the effects of ultra-fast lasers on the properties of metals and decided to try a tungsten filament (the tiny wire in the typical lightbulb).

The group blasted the tungsten filament with an ultra-fast short-pulse laser for a femtosecond. A femtosecond is to a second "what a second is to about 32 million years," according to the researchers.

The blast changed the properties of the surface metal on the filament so that it formed nanostructures and microstructures that enabled it to shine significantly more brightly while still using the same amount of electricity.

"We fired the laser beam right through the glass of the bulb and altered a small area on the filament. When we lit the bulb, we could actually see this one patch was clearly brighter than the rest of the filament, but there was no change in the bulb's energy usage," Guo said in a statement.

The change in the filament has enabled the incandescent light bulb to shine as bright as an average 100-watt bulb, but consume less electricity than the average 60-watt bulb.

Full details of the project, which was sponsored by the U.S. Air Force Office of Scientific Research, will be published in the next issue of "Physical Review Letters."

In a software-driven world, it's easy to forget about the nuts and bolts. Whether it's cars, robots, personal gadgetry or industrial machines, Candace Lombardi examines the moving parts that keep our world rotating. A journalist who divides her time between the United States and the United Kingdom, Lombardi has written about technology for the sites of The New York Times, CNET, USA Today, MSN, ZDNet, Silicon.com, and GameSpot. E-mail her at candacelombardi@gmail.com. She is a member of the CNET Blog Network and is not a current employee of CNET.
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Add a Comment (Log in or register) (34 Comments)
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by MyRightEye June 3, 2009 11:10 AM PDT
Good, work on this, we don't want mercury in our homes just to save power.
Reply to this comment
by jug831 June 3, 2009 11:26 AM PDT
Agreed. I wonder what would happen if the whole filament was zapped...would we get 100 watts worth of light for 25 watts of electricity?

It would be nice from a cost perspective also. If the bulb makers only had to add a laser like this to the production line, shooting the finished bulbs, maybe the cost would be minimal.

Also have questions as to how this laser affects the life expectancy of the bulb...
by manodud June 3, 2009 11:29 AM PDT
shine as bright as a 100 watt but consume less electricity than a 60 watt? CFL still wins by a big margin...
Reply to this comment
by rapier1 June 3, 2009 1:30 PM PDT
This seems to be the lumens put out when a portion of the filament had been modified. The questions are:
Have they tried modifying the entirety of the filament?
Have they monitored any change in lifespan?
Are there any differences in color temperature?


The color tmp issue is going to be a major one. The big problem most people have with CFLs is that they have a blue shifted light even on the 'soft white' bulbs. We seem to prefer a more yellow light.
by lusciatti June 3, 2009 11:31 AM PDT
Sounds like a promising discovery. Now if it can only be adapted to the real world and factory production, we can reap the benefits!
Reply to this comment
by wmd June 3, 2009 11:42 AM PDT
Go back to school and 5th grade math and science class... ALL of you!

If they improve the light bulb's efficiency by 80%, they barely reach that of compact fluorescents and still don't touch that of LED's.

This is nothing more than a very interesting effect that may prove very useful in thousands of applications - incandescent light bulbs are not one of them...
Reply to this comment
by Sourdust June 3, 2009 2:45 PM PDT
An improvement in the brightness of an incandescent bulb is not useful in incandescent bulbs? Stop looking exclusively at the numbers and look at the big picture. A process that can reduce the amount of energy needed for lighting and might be easy to introduce into the manufacturing process is very significant. If it works it may be equivalent to removing a few bulbs from every home, office, etc.

And congrats on your 5th grade math skills.
by MadLyb June 3, 2009 11:45 AM PDT
Yay! Anything that keeps CFL out of my house without the expense and complexity of LED is a winner.
Reply to this comment
by shamanskyh June 3, 2009 1:42 PM PDT
"How many MadLybs does it take to screw in one of those long-lasting, extremely confusing and complex CFL bulbs?"

A CFL bulb is actually less expensive when you consider the amount of time a CFL bulb lasts.
by Get_Bent June 3, 2009 2:46 PM PDT
"How many shamanskyhs does it take to soak up the mercury from CFL bulbs?"

Break a CFL bulb in your house, and you have a toxic chemical spill to deal with. And you can't dispose of the dead bulbs in the trash, either.
by MadLyb June 4, 2009 7:45 AM PDT
@shamanskyh

Clever, but you should read before trying to act smart.

The expense and complexity are for LED lighting solutions.

And to answer your riddle...none...CFL just sucks.
by TGGY4 June 8, 2009 10:27 AM PDT
The Mercury problem in CFLs is actually not as big as people make it out to be. One bulb contains about the same amount of Mercury vapour as the EPA allows you to "safely" consume each day. And about disposing them: you actually release much much more Mercury into the atmosphere if you use incandescent bulbs than you will if you use CFLs and then landfill them (Mercury from burning coal).

Besides, get some descent ones - they will last for 5-6 years.

http://www.energystar.gov/ia/partners/promotions/change_light/downloads/Fact_Sheet_Mercury.pdf
by June 9, 2009 11:40 PM PDT
@Get_Bent: nonsense. There's more mercury in a can of tuna than in a cfl bulb and you'll actually *eat* it, not sweep it up.
by techman21 June 3, 2009 11:51 AM PDT
Any improvement is welcome - the light from incandescent is so much nicer on my eyes!
Reply to this comment
by sdf0013 June 3, 2009 11:51 AM PDT
I think we've missed the point that this is the result of a "hey, what if..." kind of situation. They weren't looking for this nor were they expecting this result. The next question would be, can we enhance the result? What will changing the laser, lens, angle, structure of the nanostructures, etc. have on the metal? So many possible variables to test to see if this is just the beginning. It might not be. But we're rather premature to say this is nothing compared to CFL or LED, etc.
Reply to this comment
by Seaspray0 June 3, 2009 1:17 PM PDT
Maybe they should experiment with fuses and heating elements, too. There are several applications for filaments other than light bulbs.
by Been_there_Saw_it_before June 3, 2009 12:19 PM PDT
The mercury issue is a false fear. Yes, the CFL does indeed have mercury in it. What people do not realize that burning coal to power a 100 watt incandescent bulb over its lifetime releases far more mercury into the atmosphere than the CFL contains. Second, the CFL lasts far longer than the 100 watt incandescent bulb, thus saving even more mercury pollution.
Reply to this comment
by Truth_wins_in_the_end June 3, 2009 2:27 PM PDT
The radiation phobia with the nuclear power issue is also a false fear. More radiation is released into the environment by a coal-fired power plant to power a CFL than 10 incandescent bulbs powered by a reactor. We need to address both ends of the power problem when we talk carbon emissions and environmental impacts.
by DragonStab June 3, 2009 12:50 PM PDT
The only thing I really wonder is if they can make the efficiency equal to that of a CFL, will it last as long as a CFL or have the same life as a normal incandescent bulb? If the life expectancy is not also extended, then there is no use in doing it.
Reply to this comment
by LindseyAngell34 June 3, 2009 1:02 PM PDT
About 5 years ago researchers found a way to paint on a bio-luscence to not just ceilings but even to walls and it used very low amounts of energy...whre's that technology being used today? LEDs are getting much cheaper to build and they last for decades already. Further improvements have made them even better than the originals that we are still using...longer life, brighter and using less power...
Reply to this comment
by sslPro June 3, 2009 1:21 PM PDT
another non starter I imagine lots of r& d to be practical/ I SENSE LAYWERS licking their chops!

Leds- come on people it's the 21st century use LEDS - AS FAR AS COST our products are outstanding

and have price points of $20 to $60 for a bulb that will definetly last for 50,000 hours (a decade)

par 20 - 38 fluorescent retrofits a-19 mr16 all dimmable Great efficiency Great CRI and CCTs

Help the planet & your wallet BUY QUALITY The solid state lighting pro
Reply to this comment
by tech_crazy June 3, 2009 7:59 PM PDT
I would love to see the 50,000 hours in reality. While this may be true, I have had LEDs burn out in 3 days of continuous use when they were promised to be "long lasting"
by odubtaig June 4, 2009 5:47 PM PDT
This turkey clearly ain't voting for Christmas.
by k2dave June 3, 2009 1:40 PM PDT
I'm very happy to hear this, CF is really a joke, they last nowhere near what they claim and you unquestionably have a less colorful environment with them, they are really alchemy trying to turn mercury into gold (cost savings), but in reality don't work (try reading under CF lighting then IC lighting - there is a big difference).
Reply to this comment
by tech_crazy June 3, 2009 4:10 PM PDT
It is a matter of what one is used to. Coming from countries where electricity is a lot more expensive than the US, we are so used to reading in fluorescent light (the 4-feet ones, CFLs are relatively recent) that reading in incadescent lighting causes our eyes to strain and water.

That said, CFL light is a lot more concentrated and hence hurts to look directly at compared to the regular fluorescents where the light is more evenly spread. Also, for general aesthetics (which 3400K, 4200K fluorescents are relatively better at than 6500K ones) and color rendering, incandescents are generally better
by tech_crazy June 3, 2009 4:05 PM PDT
This does sound interesting and the points raised by previous comments were good - whole filament bombarding, life expectancy, color temperature etc.

I doubt most people will believe this, I have been using LED arrays for 2 decades now - mostly for focused lighting. Agreed that LEDs have improved with time, despite their hype (and lab results) I have yet to see commercial LEDs that give out close to100 lumen/electrical watt that CFLs commonly do, and at a reasonable price. I am beginning to lose faith in LED as a general lighting solution. All the same, CFLs have their own issues - cost, mercury etc.

If the issues in the 1st line of my comment can be reasonably taken care of this thing would zoom! Cool!
Reply to this comment
by SlimGem June 3, 2009 6:45 PM PDT
Humans should be genetically re-engineered with the self-luminescent abilities of the firefly. End of problem. Well, except that we would probably keep ourselves awake at night.
Reply to this comment
by francoisb12 June 4, 2009 8:19 AM PDT
about Compact fluorescent lightbulbs (CFLs) the question of "how green are they" is nethertheless a pending question, i suggest that we exchange information on that : http://engineering.electrical-equipment.org/energy-efficiency-news/how-green-are-compact-fluorescent-lights-cfls.html#more-791
- what is the position of Mrs Candace Lombardi about it ?
- what about the LED technology that seems promissing ...
Reply to this comment
by lighthouse10 June 6, 2009 5:10 PM PDT
Interesting development, and it would certainly increase (or allow continued ) choice.

It's wrong to ban light bulbs anyway
In fact all energy efficiency regulation, as in current House Bill, is wrong
see http://ceolas.net/#cc1x onwards


There is not any energy supply problem in society that justifies banning light bulbs or anything else:

1. Renewable energy sources already exist, and are increasingly deployed (solar, wind, wave, tidal, hydro, geothermal, biomass).
2. Nuclear energy is long-lasting and potentially renewable (short-term via breeder reactors, long-term as nuclear fusion).
3. As finite sources become scarcer, their price rises, reducing such consumption anyway, and the choice of renewable energy resources becomes more natural on the market place.
Taxes or subsidies can of course speed up the effect before then.

Emissions can be dealt with directly as described on
http://ceolas.net/#em1x onwards
Do light bulbs give out gases?
Unless you are a politician, the answer is no!

The incessant focus on "switching lights to save energy and money" is misplaced.

Consumers pay for the energy they use and should be free to use it as they wish, given that the supply is there.

All lights have advantages.
That is why they exist for people to choose.
Energy efficiency is one advantage.
Light bulbs need to have other advantages, or noone would buy them.
As it happens, light bulbs are overwhelmingly popular, bought 19/20 in the USA, 9/10 times in the EU, with similar popularity elsewhere.
Cheapness plays a big role - and why not.
But the idea that people avoid buying lights just because they are expensive is wrong - - or expensive alternatives to other products in the shops wouldn't be bought either.
Cheapness alone gives no repeated sales.
Ordinary light bulbs have a wide appeal because of appearance, a quick response also in cold conditions, a bright and broad spectrum light quality, are easy to use with dimmers and auto-switches, and can come in small sizes.
These are properties that to a greater or lesser extent no other light types share, including halogen lights, noting that halogen lights that are similar to ordinary light bulbs tend to be on the phase-out schedules anyway.

People spend half their lives under artificial lights.
One would expect politicians to respect the overwhelming choice of light people make - especially a choice made despite the extensive public campaigns not to buy such lights, and despite the promotion of fluorescent lights that are usually called "energy saving" lights.
Instead the popularity is used to justify bans, on the basis of energy savings made.

If there was a society need to save energy (there isn't), a light bulb ban would hardly be the first choice anyway, given the greater energy use of say boilers or heating equipment.
Light bulbs use about 3% of overall household energy and 15% of electrical energy in temperate climates, and replacement lights also use electricity.
More about savings and research figures from http://ceolas.net/#li13x onwards, more on the researched heat effect http://ceolas.net/#li6x

If light bulbs nonetheless needed to be targeted (they don't), then taxation is better for both government (income) and consumers (choice), see http://ceolas.net/#gg6x onwards
Reply to this comment
by sslPro June 12, 2009 6:05 PM PDT
get over it incandescent bulbs will be banned in 2012 or 2014 It will happen,

the action will be based on merit ! When people are slow adapters - I understand that

dvds or mp3 players I couldn't justify the cost vs benefits BUT regarding lighting

Leds 2009 high quality Leds (not the junk) thats whats in my house and my intelligent family

& friends houses ( we prefer $25.00 monthly bills & small carbon footprint)!!
by lighthouse10 June 12, 2009 8:24 AM PDT
Incidentally,
the comment someone made is not true, about coal power use releasing more mercury than CFLs
contain:
"What people do not realize that burning coal to power a 100 watt incandescent bulb over its lifetime releases far more mercury into the atmosphere than the CFL contains"

This is a common misconception, since it assumes coal power dominates, and also that it's untreated, which doesn't happen nowadays in any state
see details and references
http://www.ceolas.net/#li19x
In a nutshell:
1. We know where the ever decreasing coal power stations chimneys are and we can treat their mercury emissions with ever increasing efficiency at lower costs.
2. Compare that with billions of scattered broken lights on dump sites, when we do not know where the broken lights are, and so we can't do anything about them.
Reply to this comment
by sslPro June 12, 2009 5:54 PM PDT
The reality of life in the 21st century - You use tech of your time - Solid State Lighting
compact fluorescent is outdated- really outdated ! lighting solutions are about the task
of photon mgmt -- Incans & cfls spread light in an ineffecient / illogical geometric
patterns -- Leds work and prices are coming down as effeciency increases....
Leds are solutions GREAT Solutions when the're made well and Guarenteed
for 5 years have cri #s of 88 or better, sslPro
Reply to this comment
by joad2 June 16, 2009 4:39 PM PDT
Bottom line is incandescent light is THE best light..the absolute warmest light and the easiest on the eyes for reading....the only place I'm using the other crap light bulbs is in my basement and porch where I don't care if everything looks frozen in really bad light....as far as energy consumption is concerned...meh....go after the really big energy offenders in the world and leave me alone....I recycle everything, I own a really fuel efficient hybrid car, collect rain water for our plants and garden, shop at thrift stores for everything but socks and underwear, buy straight from our local farmers for our beef, chicken and vegetables and all my appliances are energy star....but LED and fluorescent light is crap however you try and spin it, new techology blah blah blah.......they are and always will be cheap utility lighting for stores, basements and anywhere you don't want to really enjoy yourself.....and your light.
Reply to this comment
by kpm16 October 7, 2009 9:02 PM PDT
Unless I missed it, no one has questioned the effects of the laser on the integrity of the tungsten filament. Filaments are designed to last a specific number of hours (life of lamp in hours). While the laser may improve light output it may be at the expense of the life of the light bulb. That would then create another energy efficiency question.
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