How to Make a Burning 1-2W 445nm Blue Laser




Introduction: How to Make a Burning 1-2W 445nm Blue Laser

About: "If opportunity doesn’t knock, build a door."
In this Instructable I will show you how to make a burning blue laser. This laser outputs 1-2W. At this power it can blind you instantly! If this is your first laser project you are in the wrong place, please find another Instructable of a lower power laser. Never point or aim this laser at; people, animals, airplanes, and reflective surfaces. ALWAYS where 445nm rated safety goggles. I recommend >OD+4.

That said I hope you find this Instructable easy and learn something about lasers.

Here is a video of the laser working:


Step 1: Parts List and Constructing Circuit

For this laser you will need...

1x M140 Laser Diode   :     Found Here

1x Aixiz Module (not needed if you buy from above link)     :     Found Here

1x 445nm Collimating Lens    :    Found Here


1x LM350

1x 100 OHM Pot

1x Standard Diode

1x 10uF capacitor

1x Perfboard

1x 1 Ohm 5W Resistor

1x Heatsink for LM350

1x Heatsink for Laser Diode      :       Found Here

Some switches or connectors (optional)

Once you get all of these parts put them together based on the schematic below.

Step 2: Enjoy

Finally you can put the laser into a case and have fun. Remember the safety rules for all lasers.




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    16 Discussions

    I have a question on this build if you have time to answer.

    I bought all the suggested parts but have assembly issues.

    Presumably on the laser diode, I remove the supplied (plastic ?) screw in collimating lens from the diode unit and replace with the glass one, but how tight should it be screwed down?

    On the unit there is a small spring that pushes against the lens part, then the supplied lens is screwed down. How tightly should the 1x 445nm Collimating Lens : Found Here be fixed? Keep the spring or not?

    Secondly. How does anyone get the laser unit to stay in the heatsink? anyone have a fix, or a supplier of screw / washers that will hold the unit in the suggested diode heatsink?

    Thirdly, could I power this with 2 x 3.7v 1000mah series Lipos for portability to move around the shed / workbench? Thanks in adv for any tips. RB

    4 replies

    The spring that sits between the diode and the lens provides tension so that the lens doesn't move around too much (closer or farther from the laser diode). The amount you screw the lens in is up to you because it determines how the laser is being focused.

    I believe the actual diodes themselves are just press fit inside a housing meant for the specific diode standard, maybe they add thermal glue? As for a larger outer heatsink they generally have a set screw that clamps the diode's housing in place.

    Those two have a combined voltage of 7.4v so that should work fine with the circuit.

    Cheers for the quick reply. My main worry was firmly mounting the LED into the listed heatsink.See dub dub dub ebay dot com/itm/Inner-diameter-13mm-Cooling-Heatsink-Heat-Sink-for-Laser-Diode-Module-/261026175391?pt=LH_DefaultDomain_0&hash=item3cc65f599f

    Obviously I am stuck in working out how to lock the led into this heatsink. I need a couple? of steel / alloy rings with threads so I can lock the led in somehow. Not knowing what such a thing is called, it may be a slow process. So if anyone has any bright ideas/suppliers I'd appreciate it. Meantime, Mr Google beckons,

    If you have your diode module it should fit inside that heatsink and lock in with a set screw which is provided with that specific item.

    Thanks for that, I can see the (very) small allen screw, what my concern was that there is a bit of an air gap between the laser unit and the heatsink unit,

    I suppose I'd thought for heat loss efficiency that the fit would be a lot more snug and that it would not just rely on an allen screw keeping it in place.

    i have a 445 2 w laser diode what rresistor value do i need to power it to its maximun ratings

    Is it LM317 or LM350 ? In the circuit you show LM317 but in component list you say LM350.

    just another safety note don't point the laser to the sky it is dangerous for planes. here in belgium there was a time the police would arrest you for doing this


    4 years ago

    What is your power supply on this?

    1 reply

    12v 7AH Sealed lead acid battery. However the voltage seemed a bit high for the lm317 / lm350 so i used several diodes in series that dropped the voltage to about 6-8V. That lowered the heat of the circuit so it was able to run much longer. A 6V lantern battery may work, however it is not rechargeable and once the voltage drops beneath the lasing voltage threshold the laser will not turn on.

    Do you also need safty goggles if you point it at the sky or only when there is a chance of reflection?
    Thank you:)

    1 reply

    This depends. When I point it into the sky I do not wear safety glasses.
    Sometimes I don't wear them inside either. But as you can see my laser is in a stable box. If you have a handheld that can roll I would always wear safety goggles unless I was outside. This is entirely up to you, but remember your eyes will not heal. If you are close to the diffused dot (reflection or not) it is BRIGHT. I am not sure the exact distance but I think if you are in within 5 feet of the diffused dot it can cause damage.

    You show the driver circuit for the red diode. Have you tried cutting dollar foam panels? My red diode can't handle white materials.

    3 replies

    I don't have a red laser :( . I put the schematic up there because it is easy for new people to understand. What mw is your red laser? Anything over 600mw should leave something on soft white foam.

    Thanks for the reply. Using driver circuits like the one you show I think I'm driving my red at about 300mW. I think I'll put the upgrade to a blue 2W on the todo list.

    Yeah, I have been meaning to move the laser into a handheld but school has been in the way :(
    If you have any other questions check out laserpointerforums.