Become a fan of Slashdot on Facebook


Forgot your password?
Power Science

Laser Blast Makes Regular Light Bulbs Super-Efficient 559

guruevi writes with news that a process using an ultra-powerful laser can crank up the efficiency of everyday incandescent light bulbs. Using the same laser process covered several years ago, the tungsten filament has an array of nano- and micro-scale structures formed on the surface making the resulting light as bright as a 100-watt bulb while consuming less electricity than a 60-watt bulb and remaining much cheaper to produce. "The key to creating the super-filament is an ultra-brief, ultra-intense beam of light called a femtosecond laser pulse. The laser burst lasts only a few quadrillionths of a second. To get a grasp of that kind of speed, consider that a femtosecond is to a second what a second is to about 32 million years. During its brief burst, Guo's laser unleashes as much power as the entire grid of North America onto a spot the size of a needle point. That intense blast forces the surface of the metal to form nanostructures and microstructures that dramatically alter how efficiently light can radiate from the filament."
This discussion has been archived. No new comments can be posted.

Laser Blast Makes Regular Light Bulbs Super-Efficient

Comments Filter:
  • by eldavojohn ( 898314 ) * <(eldavojohn) (at) (> on Monday June 01, 2009 @04:41PM (#28173229) Journal

    Laser Blast Makes Regular Light Bulbs Super-Efficient

    So that whole time in Star Wars, they were just trying to make each other Super-Efficient? That's a whole lot nicer than what I was led to believe was initially going on.

    LASIK makes a lot more sense now too.

    I'm learning!

  • by pandymen ( 884006 ) on Monday June 01, 2009 @04:44PM (#28173285) Homepage Journal
    So, considering they are as cheap to produce as normal lightbulbs, we can expect to see these on the shelves in...2050?
    • Re: (Score:3, Informative)

      by Anonymous Coward

      Never. Incandescent light bulbs are banned from Europe in a coupe of months.

      • Re: (Score:3, Funny)

        by x2A ( 858210 )

        They're not "banned", that makes us sound so draconian. It's just guideline, advice, to anyone who likes their freedom and who likes their hands being attached to the ends of their arms, not to try and buy or sell them... in a friendly kind of a way.

    • Production cost (Score:3, Interesting)

      by CarpetShark ( 865376 )

      considering they are as cheap to produce as normal lightbulbs...

      Hold on a sec. They're...

      unleash[ing] as much power as the entire grid of North America onto a spot the size of a needle point order to gain 40W of light output over the course of a lightbulb's lifetime.

      I'm having a little trouble with imagining how it could be efficient to do that for every lightbulb sold.

      • Re: (Score:3, Informative)

        Cause (huge power x femtosecond) << (small power x months).  It's right in the summary.  Femtoseconds are bloody short.
      • Re:Production cost (Score:5, Informative)

        by Artraze ( 600366 ) on Monday June 01, 2009 @07:54PM (#28175781)
        You don't seem to appreciate just how short a femtosecond is. As it is only 1e-15sec (1 millionth of a nanosecond), that means a pulse of 1e15W (1 million terawatts) would use only about 1 joule of energy.

        So let's say for the sake of argument that the power and pulse length are both an order of magnitude larger. Then say it's only 10% efficient, so that the process actually takes 1kJ. This energy corresponds to all of 25 seconds at 40W. In other words, the break even lifetime is under one minute.
  • by Verteiron ( 224042 ) on Monday June 01, 2009 @04:44PM (#28173291) Homepage

    But it doesn't matter (at least to those of us in the USA), because in 2014 incandescent bulbs will be banned.

    • Re: (Score:3, Informative)

      by Moridineas ( 213502 )
    • by freedumb2000 ( 966222 ) on Monday June 01, 2009 @04:52PM (#28173459)
      Same in europe.
    • by Chris Mattern ( 191822 ) on Monday June 01, 2009 @05:06PM (#28173665)

      Watch for sales of incandescent bulbs to triple in 2013.

    • by DragonWriter ( 970822 ) on Monday June 01, 2009 @05:23PM (#28173943)

      But it doesn't matter (at least to those of us in the USA), because in 2014 incandescent bulbs will be banned.

      This is not correct, and, in fact, the restriction that motivates this misconception is, in fact, the reason why it matters particularly to those of us in the USA. There is no restriction, first of all, of incandescent bulbs meeting one or more of the exclusions or exceptions in Section 321 of the Energy
      Independence and Security Act of 2007 (Pub.L. 110-140) [] (the law imposing the new restrictions), including:
      * Bulbs producing less than 310 lumens
      * Bulbs producing more than 2600 lumens
      * Bulbs whose operating range is not with 110 V - 130 V
      * Bulbs not intended for "general service" use
      * Bulbs that don't have a "medium screw base"
      * appliance lamps
      * black light lamps
      * bug lamps
      * infrared lamps
      * left-hand thread lamps
      * marine lamps
      * marine signal service lamps
      * mine service lamps
      * plant light lamps
      * reflector lamps
      * rough service lamps
      * shatter-resistant (including shatter-proof and shatter-protected) lamps
      * sign service lamps
      * silver bowl lamps
      * 3-way incadescent lamps
      * traffic signal lamps
      * G shape lamps with a diameter of 5 inches or more
      * T shape lamps using not more than 40 watts or having a length of not more than 10 inches
      * A B, BA, CA, F, G16-1/2, G-25, G30, S, or M-14 lamps using 40 watts or less

      But, more importantly, even for the bulbs those that don't meet one of those exclusions, they aren't banned, they just need to be significantly more efficient than they currently are. Which the improved efficiency claimed by this process (more than meet.

      IOW, if the results claimed are accurate and the process is commercially viable and this efficient for incandescent lamps generally, its quite likely that all classes of incandescent lamps (provided this process was applied to the manufacture of those covered by the Act) could continue to used in the US after the restrictions in the Energy Independence and Security Act of 2007 go into effect, because this would make those bulbs covered by the Act efficient enough to continue to be used under the limits imposed by the Act.

  • Too late (Score:4, Insightful)

    by K. S. Kyosuke ( 729550 ) on Monday June 01, 2009 @04:44PM (#28173297)
    Of only white LEDs were this efficient as well...oh wait...never mind.
  • by fuzzyfuzzyfungus ( 1223518 ) on Monday June 01, 2009 @04:45PM (#28173307) Journal
    The technique has been used to make extremely efficient light-absorbing surfaces; but hadn't been applied to light-emitting surfaces until now. Since those are two sides of the same coin, I'd have expected somebody to try it much sooner(though, I'll admit, I didn't think of it).

    On the plus side, greater efficiency in incandescents is always good(though I'd be quite interested to know how cheap laser treating filaments can possibly be). I predict that this thread will probably be infested by the "CCFLs are Evil!" brigade soon enough...
  • Consistency (Score:5, Insightful)

    by qoncept ( 599709 ) on Monday June 01, 2009 @04:45PM (#28173315) Homepage

    ... and remaining much cheaper to produce.

    ... Guo's laser unleashes as much power as the entire grid of North America onto a spot the size of a needle point.


    • Re:Consistency (Score:5, Informative)

      by sjames ( 1099 ) on Monday June 01, 2009 @05:04PM (#28173639) Homepage Journal

      ... Guo's laser unleashes as much power as the entire grid of North America onto a spot the size of a needle point.


      For one femtosecond (10^-15 seconds). Rough figure from the world factbook shows the U.S. + Canada averaging 497 GW. So, if the laser fired one thousand pulses per second, it would only draw 5 W from the wall (assuming 100% efficiency). It's another case of really big numbers combining with really small numbers to yield nothing spectacular.

    • Re: (Score:3, Funny)

      by Rogerborg ( 306625 )
      The "power [of] the entire grid of North America" is insignificant compared to the output of thousands of Slashdot nerds scattering Cheetos everywhere as their sweaty, pudgy fingers hammer out "Only for a femtosecond FRIST POST!!!!"
  • by Anonymous Coward on Monday June 01, 2009 @04:46PM (#28173327)

    Why not set an efficiency factor on a bulb(like cafe standards) instead of banning the different technologies?

    Something I never understood.

    • Re: (Score:3, Interesting)

      by Kokuyo ( 549451 )

      Oh, that's easy to answer. It's a tag. Makes it easy to spot where people have been bought to push certain agendas and fill pockets. Let me just ask you this: Do you think profit margins on old-school bulbs are a) smaller or b) larger than on more modern alternatives?

      Whenever legislation is worded in such a way that it does not encourage competition to reach a certain goal, you can bet your cute fanny that the true goal of said legislation lies not in the stated goal but in the way as to get there.

      That's ba

    • Re: (Score:3, Insightful)

      by Locke2005 ( 849178 )
      You mean like they mandated emission standards instead of requiring every car to be built with a catalytic converter? Who would be silly enough to pay for lobbying for a law that doesn't favor their own industry while penalizing their competitors?
  • Too late? (Score:2, Insightful)

    by Bruiser80 ( 1179083 )
    Too bad we won't be able to buy Incandescents any more in a couple years.... []
    unless they can get the new bulbs to 70% less power used. :-(

    The clock is ticking to 2014 (when 40watts are outlawed).

    sorry for the link, didn't have time to find a reputable site...
  • Too late (Score:5, Insightful)

    by the_other_chewey ( 1119125 ) on Monday June 01, 2009 @04:47PM (#28173363)
    Too late: Compact fluorescent lamps require about 20W for the same light output as a 100W incadescent.
    And live longer too.

    Yes, their light used to look shitty, but these times are over now as well - if you don't buy the cheapest
    there are, the light out of fluorescent bulbs is perfectly fine. And LED "bulbs" may soon be there too.
    • Re:Too late (Score:4, Informative)

      by digsbo ( 1292334 ) on Monday June 01, 2009 @04:54PM (#28173493)
      Yeah, and they contain enough mercury to poison 4000 gallons of drinking water! Yay!
    • Re: (Score:3, Informative)

      by Locke2005 ( 849178 )
      Compact florescents emit audible noise. Incandescents only emit noise if you but a cheap dimmer switch on them that chops up the sine wave. LEDs, as far I can tell, are silent. LEDs have good enough light now, they just need to be cheaper.
  • Am I the only one who thought of this []?

  • super! (Score:2, Funny)

    by u4ya ( 1248548 )
    and it only takes 11 years of operating the more efficient bulb to compensate for the energy consumed during the laser burst
    • Energy and Power are not the same. Specifically, Power is Energy divided by Time. W = E/t

      Based on just the US [], which for the sake of half-arsed napkin engineering on /. I will double to get total energy usage for North America in 2005, we're talking about 58000 TWh / 8760 h = 6.621 TW average power output.

      Thus the laser pulse itself uses 6.621E12 W * 1E-12 J = 6.621 J.

      The "efficient" lightbulb saves 40W. 6.621 J / 40 W = 0.165 s.

      So it takes less than a second to recover the energy used by the laser. I'm

      • Re: (Score:3, Informative)

        by Chris Burke ( 6130 )

        6.621E12 W * 1E-12 s = 6.621 J.


        Also, I said "power" instead of "energy" at the end of my post. Heh.

        • Re: (Score:3, Informative)

          by Chris Burke ( 6130 )

          LOL and I screwed up the exponent for "femtosecond"! At least my title is still accurate, but it's really less than a millisecond that it would take to save the energy. I didn't mean to be that half-arsed!

  • by B5_geek ( 638928 ) on Monday June 01, 2009 @04:49PM (#28173397)

    This is the might Slash. We can understand proper units.

    Femto = 10^-15

  • Lifetime (Score:4, Insightful)

    by snsh ( 968808 ) on Monday June 01, 2009 @04:50PM (#28173399)
    But long does the lamp last? It's easy to make an incandescent lamp more efficient. You just crank up the filament temp, but then your lifetime goes to pot. Lamps last 1000 hours because that's how frequently consumers are willing to unscrew and rescrew their bulbs.
  • by divide overflow ( 599608 ) on Monday June 01, 2009 @04:57PM (#28173533)
    Even if the luminous efficacy improves a 60 watt incandescent to that of a 100 watt bulb that still puts it around 29-30 lumens per watt, about 30% of a good fluorescent or LED light source.

    This is a nice improvement for an inherently inefficient and quite dated technology, but hardly but hardly "super-efficient" in the larger sense of overall luminous efficacy.
  • shark (Score:3, Funny)

    by Arimus ( 198136 ) on Monday June 01, 2009 @05:03PM (#28173625)

    So does this mean every evil genius lair is now only complete with sharks with freekin' light bulbs on their heads?

  • Conservation is a red herring: population growth will outstrip any resulting savings. Instead, we should focus on generating energy sustainably. We can do that today with a combination of wind, hydroelectric, and nuclear power.

    Conservation almost always reduces our quality of life. Why should we do that when we have the technology to not only save the environment, but improve our lives as well? We should be encouraging people to use more energy when that power makes life easier. By all rights, electricity should be cheap and plentiful.

    I can't help but wonder whether conservation advocates feel guilt over civilization itself. I certainly don't. There's no shame in using technology to make our lives better.

  • Too late. Bye bye. (Score:3, Interesting)

    by SEWilco ( 27983 ) on Monday June 01, 2009 @06:37PM (#28175019) Journal
    Too late. Incandescent light bulbs are illegal soon. Who needs technology when we have laws?
  • an added bonus (Score:3, Interesting)

    by roc97007 ( 608802 ) on Monday June 01, 2009 @07:14PM (#28175405) Journal

    I remember reading somewhere that incandescent bulbs are made somewhere in America -- Tennessee? Whereas the great majority of CFLs come from China. If incandescent bulbs can be made significantly more efficient, and they're made locally, it sounds like a win-win to me.

Matter cannot be created or destroyed, nor can it be returned without a receipt.