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HOW TO – Make a laser more powerful

How To MAKE A BURNING LASER, Save 100’s Of $$$For more of the funniest videos, click here
I’m not sure what exactly this video modded to make their laser more powerful (screw and soldered a component?) perhaps a maker out there with a cheap green laser can check it out – [via] Link.

From the pages of MAKE:
Make 715
Mini High-Power Laser by Stephanie Maksylewich in DIY: Circuits. MAKE 10 – page 140. Liberate a 200mW laser from a DVD burner. Subscribers–read this article now in your digital edition or subscribe to MAKE (use code CMAKE and get MAKE for an additional $5 USD).

14 thoughts on “HOW TO – Make a laser more powerful

  1. It’s hard to tell as it isn’t on screen for long, but it looks like he’s adjusting either a rheostat or trimmer pot. Then he bridges a resistor with solder. I think.

    Essentially he’s just feeding a higher voltage to the laser diode. This’ll reduce it’s lifespan dramatically, without really increasing its output by very much.

    But it’s a pretty cool trick, I guess.

  2. I did essentially the same thing about a year ago to my green laser pointer. Made it considerably brighter. Hasn’t burned out yet, but I only leave it on now for 10 seconds or less at a time (for overheating concerns).

  3. yeah, i second what pedro said.

    in order to extend battery life and increase the life span of the diode they use pulsed power. I’m sure there are alot more precise electronics terms out there, but basically they just switch in on and of really really fast. (on a side note this is what the LED driver chips from maxim do…). the frequency of the pulse is controlled by the pot and the resistor (or maybe just the pot and the resistor is used for voltage regulation… hard to tell!), so by cranking down the pot and shorting the resistor he’s basically just bridging the chip so there isn’t any frequency control going on, or decreasing the frequency. by doing this he’s increasing the average output of the diode to the point where it heats the match head to combustion.

    i’m not extremely sure about this part but, the light output of the laser might be changed as well. instead of only putting out the green light in a very narrow band he might have changed the output to a broader spectrum. there also might be some IR output as well. needless to say, be careful with peoples eyes!

    yes, the diode will probably fail alot sooner, but still you’re talking about ~10-100 hours in “turbo” mode vs ~1000-10,000 hrs normally. it will still last a long time just using it to light matches and amaze your friends!

    on a side note i wonder if a red match would work better. thinking about it color wise, a green laser is just light in the green section of the visible spectrum. the blue match to appear blue to us is absorbing all of the light spectrum except for blue, whereas a red match would absorb all light except for red. theoretically the red match would be able to absorb more light from the laser, heating up faster and thus igniting faster. {shrugs} it would be a cool experiment to try…

  4. a few things…

    1) the first part of this mod, the Potmod is really common… such a potentiometer exists in almost all green lasers, to fine tune the diode’s input

    2) no chance to infrared, most inexpensive green lasers are infrared light at the beginning and are then converted… however, if your laser ever shows a really dim red beam, beware, your optics are out of order and that light is really powerful in the infrared. also, i don’t believe altering current through the resistor will change the frequency, as PWM is used to control power, and the response time of lasers is well into the gigahertz range (if i recall).

    3) modifying the resistor while checking with an ammeter, a good medium between power and lifespan is around 350-400 ma draw.

    4) you can get a pretty good increase in power without trashing the diode… 5mW to 50mW is not uncommon.

    5) you can test the power of your laser with a green LED (with a green plastic casing, not a clear one) and an ammeter with a 200uA range

    connect the ammeter to the led, and shine the laser directly into it at really close range. P=uA/2.8 approximately.

  5. however, if your laser ever shows a really dim red beam, beware, your optics are out of order and that light is really powerful in the infrared

    I just soldered the resistor shown in the video and my laser now emits this really dim red beam. You say they optics are out of order, what can I do to correct this if anything? Is this powerful dim red beam good for anything?

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