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Thread: Amazed at the power of an LED laser pointer

  1. #1
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    Default Amazed at the power of an LED laser pointer

    I got to play with one the other day and was just amazed at the tight beam and throw. W O W!!!!!

    So? Why cant they make a white led laser diode thingie? Can you use optics to make a red led laser wider and how much does it reduce the throw?

    Just amazing to see that much throw from an led that takes a fraction of the power msot bright lights do.

  2. #2
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    Default Re: Amazed at the power of an LED laser pointer

    Bump, bump, bump.No one considered using a laser pointer as an led light?

  3. #3
    Flashaholic changsn's Avatar
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    Default Re: Amazed at the power of an LED laser pointer

    As I understand it, lasers are not LED's. You can use optics to focus a light beam to make it behave similar to a laser, but most people want some spill and don't want a really tight spot, especially as tight as you find with laser pointers. Imagine how useful a white light would be if it was focused to a 1/4" dot - even if you could see it 50 yards away or further. Actually you probably couldn't see anything far out other than the trail of the light...
    Just my opinion...
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    Flashaholic changsn's Avatar
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    Default Re: Amazed at the power of an LED laser pointer

    Forgot to mention one point, I don't think you want to use a laser as an LED light, unless you want to hurt someone...
    Sam
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    Flashaholic* FirstDsent's Avatar
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    Default Re: Amazed at the power of an LED laser pointer

    I frankly didn't understand your post. What exactly are you talking about? Describe the device you used.

    Here's why I'm confused:
    lazers and LEDs are not the same thing, nor can they be made to do the same thing. I have seen small pen-light type things with a small LED in one end and a lazer in the other, I would call it an LED/lazer, but it doesn't sound like that is what you're talking about.

    Lazers are coherent light. they emit only one wavelength of light, and are dangerous because your eyes cannot handle much light at a specific wavelength. If you were able to "spread out" the beam, it would still be dangerous because the amount of light at the specific wavelength would still be high enough to damage eyes. Because all their energy goes into making only one wavelength of light, they appear brighter than their power would suggest. However an LED is putting out much, much more light.

    LEDs emit light in a broad spectrum of wavelengths. Some of these wavelengths are not even visible to the human eye. This is not coherent light. The result of all the red, orange, yellow, green, blue, and violet colors appears white to our eyes. It may appear different to animals and aliens.

    Will someone more familiar with lazers please explain how they emit such a collimated beam? Suffice it to say, that an LED cannot be collimated into a beam as small as a lazer as far as I know. If one could, it would be horribly dangerous.

    Bernie
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  6. #6

    Default Re: Amazed at the power of an LED laser pointer

    An LED or a laser diode is basically descided upon at the time of its creation. A laser diode has a laser cavity with both ends cleaved off. This provides enough reflection for the lasing process to begin.

    A LED has a much larger die and produces light the is not coherent and does not contain a laser cavity.

    This is why a laser diode can't be white..as white contains more then one wavelength. A white laser pointer would have to consist of a red green and blue laser diode and then have their beams superimposed onto each other. This would be an expensive rather bulky unit.. not really a pointer.

    Another way would be to have a VSCEL laser diode designed in such a way that uses three laser cavities each producing Red, Green and Blue. In vague terms the lens would have to focus all of them somehow and then it may be possible... however this technology does not yet exist.

    So although the two are similar in some regards... they are also very different technologies.
    Last edited by Athoul; 04-24-2006 at 01:07 AM.

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    Default Re: Amazed at the power of an LED laser pointer

    Sorry... I lost this thread when it was moved.

    I played with a laser point that shoots out a red dot and uses a few button cells. I am assuming its a diode thingie since its so small and compact and required 3 batteries. I can only assume because of its size and use of 3 batteries its LED based.

    You got a point, a quarter inch dot would be rather useless unlesss you wanted to point stuff out. Wonder about a 4 inch dot? Yes, I know thats what they make flashlights for, but it was just a wacky idea I had.

  8. #8

    Default Re: Amazed at the power of an LED laser pointer

    The 3button cell pointer you have is probably a <5mW red laser diode pointer. So it is a laser, not an LED.

  9. #9
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    Default Re: Amazed at the power of an LED laser pointer

    Quote Originally Posted by FirstDsent
    ....... your eyes cannot handle much light at a specific wavelength. .......

    Bernie
    I don't think the substance in our eyes is that choosy. Its not convincing anyway.

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    Enlightened Soniq7's Avatar
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    Default Re: Amazed at the power of an LED laser pointer

    I use my wicked fusion for a flashlight all the time. It lights up the whole room. And throw? So far it feels illegal.
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  11. #11
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    Default Re: Amazed at the power of an LED laser pointer

    Quote Originally Posted by cobb
    Bump, bump, bump.No one considered using a laser pointer as an led light?
    As a flashlight, you mean? I removed the collimating lens
    from an old greenie, so now its divergence is something
    like 2 or 3 degrees. It makes a really bright spotlight.
    If you added a negative lens to spread the beam even
    more, you could easily use it as a flashlight. Shouldn't
    be dangerous with the beam spread out that much, but
    it wouldn't be the brightest flashlight in your drawer.

    Interesting idea, though -- laser diodes are supposed
    to be a very efficient light source.

  12. #12
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    Default Re: Amazed at the power of an LED laser pointer

    I took a lense and fooled with the laser pointer. It widen the beam to that of a single red led light and man, it lost its throw. I got almost a 3/4 inch circle on my white t shirt in a lit room then it was almost not visible.

  13. #13
    Flashaholic jkaiser3000's Avatar
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    Default Re: Amazed at the power of an LED laser pointer

    such is the nature of lasers .

    Lasers can have a small amount of light, and can deliver that a very long distance. Flashlights, on the other hand, have more light delivered a lot closer.

    I could only imagine the result if we could collimate a 1watt luxeon led (compared to your 5mW pointer). Sadly, that can't be done, at least not in the way a laser is collimated

  14. #14
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    Default Re: Amazed at the power of an LED laser pointer

    I use to think lasers were silly except for industrial uses, but now I have played with one, man. Amazing how so little light can be put into a thin beam and how that beam travels.

    I can just imagine the thrill of having one to pop balloons, etc.

  15. #15
    *Flashaholic* PhotonWrangler's Avatar
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    Default Re: Amazed at the power of an LED laser pointer

    To further clarify the issue of LED vs laser, you have a diode-based laser. If you connect a red laser pointer to a variable power supply and turn the voltage down until it falls just below the lasing threshold, you have an eye-safe (and rather expensive) red LED.
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  16. #16
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    Default Re: Amazed at the power of an LED laser pointer

    Man, I put in another battery as the stock one read replace on a battery meter. Man o man. It was brighter, bigger spot and it seemed to shimmer with silver sparklies in the beam center. I shown it all around my parents peoperty and the throw was amazing.

    PW, I put the stock battery back in it and left it on for two days. It became a dull barely lit red led and I looked into it. First I sweeped my face to test the brightness and found it was really dim. I looking into the beam and it too had the same shimmering movement inside the beam center. Didnt see any lotto numbers or anything like that though.

  17. #17
    *Flashaholic* PhotonWrangler's Avatar
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    Default Re: Amazed at the power of an LED laser pointer

    That must have been operating right at the verge of lasing threshold on those weak batteries. I've experimented with a numbe rof laser diodes on a bench setup and the transformation from LED to Laser at lasing threshold current is striking.

    BTW I accidentally zinged myself in the corner of one eye once. I bumped a laser on the bench, and at the same instant, it spun around and the power supply glitched and shot a slightly "warm" blast into the corner of my right eye. I actually felt a brief burning sensation.

    That shook me up badly enough that I disassembled the test circuit, shut everything down in the lab and went home!

    I followed up with an appointment with my opthamologist a couple of days later, and fortunately there was no damage to my eye. This event shook me out of the "it will never happen to me" mindset!

  18. #18
    *Flashaholic* IsaacHayes's Avatar
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    Default Re: Amazed at the power of an LED laser pointer

    The shimmering effect is cool. I see it with every red laser I've seen. It's like TV static.

  19. #19
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    Default Re: Amazed at the power of an LED laser pointer

    Amazing how a solid state device can have what appears to be moving parts.

  20. #20

    Default Re: Amazed at the power of an LED laser pointer

    The effect is neat, I have an arctile somewhere I had found on the net awhile back that went into great detail about this effect. Also an interesting thing. if the dots do not appear to rotate then you have good vision, if they rotate left or right it means you have near or far sightedness to a degree. I can't remember at the moment which direction ment what..but I thought it might be of some interest.

    Anyway I saw something earlier on in this thread, I'm not sure if it was awnsered or not. That was something about your eyes being able to handle more of certain frequencies then others. This is not true, certain frequencies will appear not as bright as others, however because your eyes have no pain sensors there is no feeling of damage occuring even if the beam seems to be dim. A 100mW 670nm red laser will do similar damage to your retina as a 100mW 532nm green "bright" laser. Usually damage is not detected till a couple days later. Always know that any frequency in the visible light spectrum will basically have the same effect on your retina and use caution while operating any laser. Those in the far IR will instead damage your cornea, etc.. very bad also but a slightly different injury. Make sure you take safety into consideration first and are using goggles designed for the wavelength of the laser you are operating.

    I hope this might clear some that up a bit,
    cheers,

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