# How to build a laser (general guide)

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## Step 1: What do I need to build a laser?

Basically, you need:
laser diode (LD)
collimation optics
current regulator (aka driver)
power supply
heatsink
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
etc...
Hamzafarooq says: Mar 17, 2013. 12:16 AM
what is the voltage & Amps of a red laser diode?
(I am using a 22x HP DVD R\W Drive red laser diode...)
3zuli (author) in reply to HamzafarooqMar 17, 2013. 5:08 AM
16x...200-250mA...<200mW
22x...300-400mA...250-300mW
Start at 300mA to be safe.
HFraza says: May 27, 2012. 2:41 PM
please tell me the voltage of laser diode
3v,
4v
or +7.2V
3zuli (author) in reply to HFrazaMay 27, 2012. 8:10 AM
what diode are you using?
Electorials says: Aug 4, 2011. 5:46 AM
"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?"

lol that was funny :D

There's something I don't really understand:
16x...200-250mA...<200mW
22x...300-400mA...250-300mW

In these examples, it means that the diode will run at
U=P/I = 200mW/250mA = 0.80V
U=P/I = 300mW/400mA = 0.75V

Isn't that voltage Really low?
Datasheets say that a dvd burner diode runs at +- 4V ?!

Also, the power (e.g. 200mW) is that electrical or optical power?
3zuli (author) in reply to ElectorialsAug 6, 2011. 7:24 AM
the power I'm talking about is the optical output from laser diode. the electrical power is greater.
Electorials in reply to 3zuliAug 6, 2011. 9:21 AM
Ok.

And what is the average efficiency value of a DVD burner diode?
(Output power / Input power)
3zuli (author) in reply to ElectorialsAug 7, 2011. 2:48 AM
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
http://www.lasersurplusparts.com/images/LEC_LPC-815-red.png
Electorials in reply to 3zuliAug 7, 2011. 3:44 AM
Ok, Thank you ;)
HFraza in reply to ElectorialsMay 27, 2012. 7:49 AM
how to make it without module
HFraza says: May 27, 2012. 7:46 AM
please tell me the voltage of laser burner
cas2406 says: Nov 20, 2011. 5:22 AM
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 (author) in reply to cas2406Nov 20, 2011. 6:11 AM
1. what PSU are you using?
2. is the laser focused?
cas2406 in reply to 3zuliNov 20, 2011. 10:28 AM
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 says: Nov 18, 2011. 7:14 AM
do u really need to use a module?
3zuli (author) in reply to DreisteinNov 18, 2011. 10:49 AM
well, you don't have to, but it's just so much easier to use one, and they are pretty cheap (around \$4)
The nerdling says: Jul 26, 2011. 4:57 PM
can i use the power from a tomcat torch and/or a 3v power suply?
The nerdling says: Jul 26, 2011. 4:55 PM
can i connect a 3v power supply to my diode without anything else mabey a diode?
instructanator says: Jul 16, 2011. 1:04 PM
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. :)
3zuli (author) in reply to instructanatorJul 16, 2011. 11:51 PM
of course, the power supply has to be powered on while adjusting the current
instructanator in reply to 3zuliJul 17, 2011. 5:30 AM
Yea, that was a little stupid of me. Just making sure.
instructanator says: Jul 8, 2011. 10:21 AM
I have been looking for a resistor for the test load.  I found over a hundred 1 ohm resistors on digikey, and I'm kinda confused.  Could you give me some more info on which to use, or does it not matter for this application as long as it is 1 ohm?
3zuli (author) in reply to instructanatorJul 14, 2011. 4:57 AM
you should use a resistor that is rated for at least 1W of power. the common 1/4 or 1/2W resistors can't handle bigger currents. so get a 1ohm 1W (or any higher wattage)
instructanator in reply to 3zuliJul 16, 2011. 12:55 PM
Thank you!
Dimitrioptimus says: Jun 11, 2011. 2:02 PM
thankx 3zuli again

Actually lilbit confused of what axis module to purchase,in axis store I saw various 12*30mm modules but these have different specs ie,

1>AixiZ 120° Line Generator for 12x30mm Housing
2>AixiZ 38° Line Generator for 12x30mm Housing
3>AixiZ 60° Line Generator for 12x30mm Housing
4>AixiZ 89° Line Generator for 12x30mm Housing
5>AixiZ 9mm Cross Hair Lens for 12mm Casing

donno which one to purchase so that I get a maximum burning with LPC815 Red Laser Diode.
3zuli (author) in reply to DimitrioptimusJun 12, 2011. 2:25 AM
those lenses won't give you a dot, but a line or cross. to get a dot shaped beam, you need this:

and to get the most burning power, you need this AR coated lens:
http://www.aixiz.com/store/product_info.php/cPath/28/products_id/60/osCsid/c2d8dafd1f5eaab5671f0e8ee4d64784
Dimitrioptimus says: Jun 6, 2011. 11:34 AM
Thank u very much 3zuli for responding so quickly indeed it was very helpful

I have some more questions so plz respond

1>I will purchase TrustFire TR-001 Multi-Purpose Lithium Battery Charger but which battery will be best suited for this project plz mention type,made & manufacturer.Plz give the site name if possible,from where shipping is low or free cuz I live in India.

2>I want to use LPC-815 diode with it with asiz module,does glass less increases the efficieny about 10 to 15%

3>U mentioned to use a good heatsink,my heatsink has 2.2cm*1.5cm*1cm is it ok.

4>Is stonetek corporation is good for buying LASER HEATSINK MODULE & LASER DIODE?

5>I want to buy blue laser diode,plz mention which will be most powerful which are commercially avaiable(plz mention the site name if psble)

6>Is LM-350 can replace LM-317 in this project as LM-350 can handle 3amps with same refernce voltage as lm317 as a result less geat will generate n smaller heatsinks can be used,plz give suggestion if I right or wrong

3zuli (author) in reply to DimitrioptimusJun 7, 2011. 1:19 AM
1. for a first project, I'd recommend the 14500 batteries, since they are of the size of a AA battery and you can use standart 2x AA battery holder. I'm using TrustFire 14500's from DX, the link is in the "Power supply" step

2. the glass lens should be a bit more effective, there are also lenses with AR coating for red lasers that can increase the effectivity with about 10%

3. the point is to make the best contact between the laser module and heatsink. see the "Final phase" step for inspiration on this

4. stonetek is very reputable and has 100% reputation

5. what wavelength (or color) do you want? 405nm (violet) - the most powerful diodes (known as the "12x") can be pushed to 500mW and more; 445nm (blue) are commonly run at 1.2-1.7W. iirc, both can be bought at stonetek but I strongly recommend you that you should first build some low powered cheap red laser, practice diode harvesting and soldering, BUY PROPER LASER GOGGLES and only after that startt building high powered lasers.

6. LM350 can be used, but you must still heatsink it
Dimitrioptimus says: Jun 4, 2011. 1:51 PM
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(http://www.candlepowerforums.com/vb/showthread.php?257543-LiIon-18650-battery-comparison)but cant decide which one to purchase.

3zuli (author) in reply to DimitrioptimusJun 5, 2011. 12:41 AM
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: http://www.dealextreme.com/p/trustfire-tr-001-multi-purpose-lithium-battery-charger-12594 It's a bit slow but works, this one is quick charger (and can fit some bigger batteries too): http://www.dealextreme.com/p/ultrafire-wf-188-rapid-charger-for-3-2v-3-7v-lithium-batteries-100-240v-44091

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 :)
nothinglabs says: Apr 22, 2011. 1:02 PM
thanks for posting this - very useful.
jmcvay says: Apr 17, 2011. 2:41 PM
a file only cuts going one direction, you will dull it going both
kelseymh says: Apr 14, 2011. 10:06 PM
So, you're not actually telling us how to build a laser. You're just telling us how to build the housing and driver circuitry for a pre-fabricated laser diode.
3zuli (author) in reply to kelseymhApr 15, 2011. 1:05 AM
yes, but this is the info that most beginners consider as "how to build a laser". this is written mainly for beginners.
everybody must start somehow, with something easy to build and understand
iminthebathroom in reply to 3zuliApr 16, 2011. 8:19 PM
Yeah, I can see it as still quite useful