Introduction: How to Build a Laser (general Guide)

Step 1: What Do I Need to Build a Laser?

Basically, you need:
laser diode (LD)
collimation optics
current regulator (aka driver)
power supply
something to house all the electronics (project box is ok for a first build)

then  you can add other optional things:
safety switch
LED for power indication
cooling fan

Step 2: What Tools Do I Need?

You need:
soldering iron
DMM (digital multi meter, even the cheapest works fine)
some wires (the more flexible the better)
small pliers

other useful tools:
3rd hand

Step 3: Step 1: Gathering the Laser Diode

Here you have 2 options:
either to get a DVD drive for pc and extract only the diode assembly (aka sled).
or buy just the laser assembly from the internet.

You can get old DVD RW drives on ebay for >15usd, or just look around and ask friends if they don't have some old unused drives.
The another option is to buy just the sled ftom internet.

My favourite e-shops for laser components:
on these sites search for LPC-815, this is the most commonly used red laser (22x write speed).

What if I can't find the LPC-815, if I have only 20x or 16x burner, or if I'm not able to determine the write speed?
First, use google to find out something about your drive (search for part numbers from the label), this should bring out enough information. Remember the write speed.

You must extract the diode from the sled. This video shows the process:

if you have other model of dvd burner, set your DMM to the DIODE TEST mode and test both diodes using the pinout below. When you see bright red light, you've got your diode :)

Step 4: Step 2: Collimation Optics

This is needed to make the actual laser beam. Without this lens, you would have just a very wide, useless spot.
The most common colimator is  called Aixiz module, and it serves as the holder for both the diode and lens.
The diode is being press-fit into the module, using vice (see the pics).
You can buy it from the e-shops I mentioned in previous step

Step 5: Step 3: Driver

What's this?
This is used to regulate the current flowing through the diode.

Do I need this?
YES! You must NEVER connect the LD directly to the power supply because it WILL die!

Can I just use a resistor?
Theoretically yes, but the current will not stay constant as the components heat up and the battery voltage decreases and this can shorten the diode's life.

But kipkay didn't use any driver...
Why do you think we have to deal with n00bs crying about their dead Laser Burning Flashlight Hack? (Just read the text above...)

A lot of people ask me about the diode's forward voltage stuff. This is a constant current driver. That means, it will adjust it's output voltage in order to keep the optput current fixed. So, it doesn't matter if you connect a red (2.2V), IR (2V), 405nm or a 445nm (>4V), as long as your power supply's voltage is above the diode's voltage + 1.5V, your laser will be running fine at the set current.
Also, the answer to question: "What voltage is diode XY?" can't be answered directly. Every diode's forward voltage (Vf) depends on her type and on the current. For example, a LPC-815 has Vf from 1.8V up to about 3.2V, as the current increases. Every diode has a PIV plot, which describes it's dependancy between the current, optical power and voltage. Google your diode's PIV plot, such as "LPC-815 PIV" or "22x red PIV" and so on.
Since we're building a red laser here (based on LPC-815), here's the PIV plot for LPC-815:

You can either buy one or build one (if you can)
the most common commercially sold drivers are:
and (usage instructions:

The most common DIY driver is called DDL driver and it uses LM317 as current regulator.

you will also need a thing called TEST LOAD, which consists of 4 1N4007 diodes and 1 1ohm resistor wired in series (check the pics). To use it, connect the output terminals of driver to test load (+ on the diode's anode, - to the resistor) and measure the voltage across the resistor. With 1ohm resistor, 1mV of voltage equals to 1mA flowing through the setup. Now rotate the small potentiometer, until the DMM reading matches your desired current.

recommended currens for various diodes:

Step 6: Step 4: Power Supply

Most beginners use 9V battery to power their first build, but 9V batteries have very small capacity and can't supply high currents (>350mA) for long times. Laser with 9V
battery at 350mA will burn for the first 60 seconds or so and after that the laser stays at <100mW and can't burn anything.
Now you must decide, if you want to build a portable laser or "labby" style, which just sits on the desk, powered by wall PSU.
The second option is easier, any wall PSU that puts out at least 8V at 500mA
If you want a portable build, the best option is to use Li-Ion batteries. The most popular are the 18650 's, but there aren't any battery holders for 18650, so easier is to use
14500 (AA size) or 10440 (AAA size), which can be used with standart AA/AAA holders. Don't forget to buy a proper charger .
Now, just connect it together using the schematic below. Pay attention to the pinout, if you connect it wrong, the diode WILL die

Step 7: Step 5: Final Phase

The last thing you need (or you should have) is the heatsink. Just find some small heatsink (good heatsinks are usually inside old CRT monitors), on which you can easily mount your laser module. Thermal epoxy (like Arctic Silver) is your friend :)
Or you can buy this one:

Now, let your imagination take over and build all this stuff into some nice project box.

Step 8: And What Now?


AvaH9 made it!(author)2017-04-14


Thanks for all your explanation, it was extremely helpful!
I have the circuit and it works well, I am always monitoring my current and use the minimum allowable current to drive my laser so I am pretty sure I am not over driving it, the circuit works fines for days but sometimes it burns my laser very slightly, in the sense that the light gets dimmer!
I found out that if I don’t discharge my capacitor and chance the laser diode it would be burnt, What else may cause the problem?

My laser diode is D6505 and I am driving it with 20mA!


3zuli made it!(author)2017-04-15

Yes, not discharging the capacitor will most likely kill the diode when you connect it. Lasers are also sensitive to electrostatic damage, you can sometimes kill them just by touching them.
The other vulnerable part is the potentiometer, it might not be able to handle the dissipated power, although at only 20mA you should be still fine. Anyway, you can calculate the required resistor value for your desired current and simply use a fixed-value resistor instead of the potentiometer. You can use a calculator such as
Lastly, you should put the diode into a proper focusing module/heatsink. It serves as a heatsink and also protects the diode mechanically.

KuldeepS64 made it!(author)2017-02-22

how to make small laser hair removal machine. Like this handy machine or very laser hair removal machine

StuartB44 made it!(author)2016-03-27

I did'nt see it mentioned anywhere about keeping the tab on the LM317 away from the laser diode case.

The tab is connected to the Positive Output of the 317 and the laser case is Negative/Ground. If they touch you would get a short circuit.

In one of your photos it looks like they are touching each other.

3zuli made it!(author)2016-03-28

Yes, that's right. It's not shown very well in that photo (step 7, photo 2), but the LM317 is actually insulated by a heat sink gasket and the bolt also has an plastic insulating washer.

StuartB44 made it!(author)2016-03-28

Ok 3zuli. Thats good to know.

anjoze made it!(author)2016-03-23

I'm trying to reproduce the laser driver. It turns on but the laser doesn't burn anything.

The design is the same and the laser switch on and it can get to 240mA. If I change the 2 resistors (10ohms) for 3 I can have 350mA. Even like that It doesn't burn... :(

My AIXIZ module is this

Thanks for any help

3zuli made it!(author)2016-03-24

If you're sure that you used a diode from a DVD-RW drive (not a DVD-ROM, those don't have enough power), then it looks like the diode is damaged. It could have been either mechanical or electrostatic damage (ESD) during removing the diode from the drive, ESD or overheating during soldering, or the initial current was simply set too high and it destroyed the diode. After any of those events, the laser diode breaks down and keeps operating as a LED diode, but has minimal output power, so that's why it doesn't burn anything. Just get a new DVD-RW drive (or just the laser assembly itself) and try again, eventually you'll get it right :)

marek.sefl.3 made it!(author)2015-02-27


can someone help me here please ?

I had 4 red laser diodes form DVD readers/burners. I used exacly this LM317 driver

connected to 7.5V 1.5A power supply.

I set the driver to produce around 60mA. All 4 diodes were OK. The problem was all 4 diodes after 20sec just reduced their brightness for around 10%. After 2 diodes i thought the diodes just getting damaged from heat. But i tried to hold the third and fourth diode in hand without heatsink and they weren't even heating ! And same thing happened.

This issue is permanent for the diodes and it happened to me also with more powerful IR diode.

Any ideas ?

Thanks a lot !

ptkrf made it!(author)2016-01-09

You must know the operational power of the diode and adjust control circuit accordingly.

When you slightly damage laser diode, it starts to function as a normal LED (it becomes trash). Perhaps that is what happened to you and you didn't notice heat output after.

Also LM317 adjusts voltage so that correct current flows through and if diodes's resistance went up, LM317 could've run out of input voltage (diode demanded more than 7.5V - 1.7V [Lm317 takes that much for itself]).

ptkrf made it!(author)2016-01-09

You must know the operational power of the diode and adjust control circuit accordingly.

When you slightly damage laser diode, it starts to function as a normal LED (it becomes trash). Perhaps that is what happened to you and you didn't notice heat output after.

Also LM317 adjusts voltage so that correct current flows through and if diodes's resistance went up, LM317 could've run out of input voltage (diode demanded more than 7.5V - 1.7V [Lm317 takes that much for itself]).

DerpS made it!(author)2015-08-17

60 mA is probably not enough to power your diodes. The current may differ between diodes, so check the datasheets.

Yonatan24 made it!(author)2015-08-05

I know almost nothing about lasers but maybe the voltage they were getting was too high

JeromeS16 made it!(author)2015-11-19

Great job man! hope you keep it up

E1024d made it!(author)2015-06-02


how to connect three legs of VR


aephy6 made it!(author)2015-03-22

Hi, This is the "Sony DVD-RW : DRI-190A" laser part which wirtes DVDs on 20x, i want its laser for using in mini CNC machine, but there is two laser diode in this model, i cant distinguish which one should i use, and i dont know about the model of laser diode too, any idea?
Left one, or Right one?

<I know i can test them and select the stronger one, but i just wanted your ideas>

zepplica made it!(author)2015-03-07

just for clarification, how is the test circuit suppose to be used? just hook it up the the driver circuit to check the resistance right?

gul.m.rafiq made it!(author)2015-02-20

hello sir ,
i am working on same project

i used dvd rw laser for my project. I follow the circuit diagram given above but laser is not upto the mark not focus and not burning paper or any other things. Is this problem is due to lens that i havent used yet or any other thing ?

plz help

3zuli made it!(author)2015-02-22

You need to use a focusing lens in order for the laser to burn stuff. Otherwise you just get a wide beam which is very weak.

john1a made it!(author)2014-07-30

I Made it! Actually I made all this laser using a NDV 4542 405nm diode at 120mA using this driver. I also made gerbers (PCB schematic) for this driver and uploaded it in this comment.

You can see my build (CNC Laser Engraver) in my profile.

yamahapower made it!(author)2014-06-23

Your LM317T schematic is WRONG, my friend!

Middle leg is the output leg.

3zuli made it!(author)2014-06-23

This schematic is OK. Your schematic is the LM317 as a constant voltage source, which can not be used to drive laser diodes.

In this case the LM317 is connected as a constant current source:

The current goes from the OUT pin, passes through the resistors creating a voltage drop, which is then sensed by the ADJ pin and compared to the internal 1.25V reference. LM317 will adjust its output voltage to get 1.25V on its ADJ pin, which in this connection results in a constant current supply.

Quin5 made it!(author)2014-05-15

I'm looking to purchase a lazertag system to start a lazertag business,
would you be able to produce or lead me to the guns and equipment I need
that would be safe and certifiable, that would be a cheaper option than
the $600/gun price range that I've seen advertised by the lazertag
manufacturers? email if so at

3zuli made it!(author)2014-05-18

This is the cheapest lasertag I know about:

It will cost $119 per gun (DIY kit), but it's still in development. However if you want to make a business, I would rather rely on ready-made lasertag systems which are already certified, reliable and safe to use. As a lasertag business, the last thing you want to deal with are blind customers.

Dimitrioptimus made it!(author)2011-06-04

PLZZZZZ clarify my doubts

1>want to know that if I use Li-Ion batteries i.e; 18650 which are 3.7v 2600maH,then I have to use 3 of them connected in Series is that right(about 11.1 v )(since the total consumption will be about 7.2v),but these batteries comes with pcb protection so when I will be using this laser will the pcb should posses any problem.Secondly want to know that if this driver can handle 2600mah.

2>Then in case 14500 which is standard AA(1.5)then have to use 5 of them I guess,plz clarify if I am right or wrong.

3>Can u plz give the names of the chargers which charges these batteries,1 by 1 charging will not be a problem for me.

4>plz suggest the best lion battery manufacturers. I went to this site( cant decide which one to purchase.

Thankx in advance

3zuli made it!(author)2011-06-05

1. what diode are you using? because for red or IR laser 2 LiIon's are enough, but for bluray or 445nm you need 3 batteries. Also, don't forget to properly heatsink the LM317, it will get toasty ;) The protection PCB is mostly your friend, it just monitors the battery and keeps it from under- and overcharging and disconnects the load, if the current is too big. The 2600mAh number is the capacity of battery, the higher, the better - the more power can be stored inside and the longer is the runtime.

2. 14500's are 3.7V LiIon's too, so you have to use 2 or 3 of them

3. I'm using this one: It's a bit slow but works, this one is quick charger (and can fit some bigger batteries too):

4. You don't have to use those $15 AW IMR batteries, in fact those cheap 18650's and 14500's I linked in this step are good enough (I'm using both, drawing 1.5A from 18650 and 0.8A from 2 14500's in series and they preform well)
hope I helped you :)

Quin5 made it!(author)2014-05-15

I'm looking to purchase a lazertag system to start a lazertag business,
would you be able to produce or lead me to the guns and equipment I need
that would be safe and certifiable, that would be a cheaper option than
the $600/gun price range that I've seen advertised by the lazertag
manufacturers? email if so at

CCube55 made it!(author)2014-04-06

can I use the G9105 regulator???

3zuli made it!(author)2014-04-18

G9105 is a 5V fixed voltage regulator. I've seen some people build laser drivers using fixed regulators, but I don't think it's the best idea. Adjustable regulators such as LM317 are way better for this. If you are interested in the low dropout voltage, try the LM1117 which is a low-dropout variant of LM317.

brooksby made it!(author)2014-04-18

I cant get a 35mw laser diode burning with the standard laser circuit ie.9v lm31t.

what could the problem be?

3zuli made it!(author)2014-04-18

35mW is not enough for burning. Generally you need at least 100mW to burn stuff, so I recommend you to buy a stronger diode.

sonubachhav made it!(author)2013-12-23

for metal cutting what i can do...?

army_knife made it!(author)2013-07-14

Hi, I want to build a ~150mW 532nm green laser, but am not quite sure how to.
I have a flashlight housing with 2x 3.7V batteries, which i bet I can fit the laser into
I want to buy all the pieces online so that I can assemble the laser when they arrive,
but seems like no one is selling a laser diode nor driver,
I am want to spend <35$,
is this possible? if so, can you reffer to a ebay seller, or maybe share some links?

3zuli made it!(author)2013-07-14

This is not possible for < $35 (unless you get the module as a gift from someone :D ). Just the laser module will cost you $40-50, for example this one: , which should output 100-150mW.
These modules can't handle 2 3.7V batteries, so you can either replace the original driver with one that can run from 7.4V, or you can build a spacer that will fit inside the battery tube and will replace one of the batteries, so that you only get 3.7V. It's also recommended to connect a diode (1N4007) in series with the module, because some modules might get burned from fully charged LiIon cells (4.2V) and the diode reduces the voltage by about 0.6V.
I recommend you to go to and view the Green lasers section and try searching for "green laser tutorial" or so, I am sure you will find lots of informaton and ideas for your build :)

Hamzafarooq made it!(author)2013-03-17

what is the voltage & Amps of a red laser diode?
(I am using a 22x HP DVD R\W Drive red laser diode...)

3zuli made it!(author)2013-03-17

Start at 300mA to be safe.

HFraza made it!(author)2012-05-27

please tell me the voltage of laser diode
or +7.2V

3zuli made it!(author)2012-05-27

what diode are you using?

HFraza made it!(author)2012-05-27

how to make it without module

HFraza made it!(author)2012-05-27

please tell me the voltage of laser burner

cas2406 made it!(author)2011-11-20

hi there

i did every thing as you did but i can't get the laser to burn, could you please help me? i used the same parts (laser diode, parts for the driver).

3zuli made it!(author)2011-11-20

1. what PSU are you using?
2. is the laser focused?

cas2406 made it!(author)2011-11-20

I am using a dell PS-5161-1D PSU
Output: at 5V, max 11A, 85W max
at 12V, 9A max, 160W max.
i have tested at both voltage. and the beam is focused

Dreistein made it!(author)2011-11-18

do u really need to use a module?

3zuli made it!(author)2011-11-18

well, you don't have to, but it's just so much easier to use one, and they are pretty cheap (around $4)

3zuli made it!(author)2011-08-07

I don't remember the exact efficiency, each type of diode is a bit different. for example, this graph is for lpc815 (22x) burner diode

3zuli made it!(author)2011-08-06

the power I'm talking about is the optical output from laser diode. the electrical power is greater.

The+nerdling made it!(author)2011-07-26

can i use the power from a tomcat torch and/or a 3v power suply?

The+nerdling made it!(author)2011-07-26

can i connect a 3v power supply to my diode without anything else mabey a diode?

instructanator made it!(author)2011-07-16

Sorry, but I have one more question. When measuring the voltage to adjust my driver's pot, should the power supply be on? I imagine it should, but I just want to make sure since the power supply comes in the step after you adjust your driver. Maybe I worry too much, but I don't want to fry my diode. :)

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