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
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...

Step 2: What tools do I need?

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

other useful tools:
tweezers
vice
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:
http://modwerx.com/shop/
http://hightechdealz.com/
http://stonetek.org/shop/
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...)

UPDATE
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: http://www.diy-lasers.com/images/LEC_LPC-815-red.png

You can either buy one or build one (if you can)
the most common commercially sold drivers are:
http://www.modwerx.com/shop/laser-diode-drivers-test-loads-c-10/adjustable-laser-diode-driver-circuit-assembled-red-or-blu-ray-p-8?zenid=heee48kk0ak9008r2v8oo60cn7
and
http://laserpointerforums.com/f64/lava-micro-flexdrive-driver-lavadrive2-fits-pens-22502.html (usage instructions: http://hacylon.case.edu/ebay/laser_diode/MicroFlexDrive_V5_manual.pdf)

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:
16x...200-250mA...<200mW
22x...300-400mA...250-300mW

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: http://www.laserlands.net/heatsink-12mm-yh.html

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

Step 8: And what now?

Comments

[Hamzafarooq]

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

[3zuli]

16x...200-250mA...<200mW
22x...300-400mA...250-300mW
Start at 300mA to be safe.

[HFraza]

please tell me the voltage of laser diode
3v,
4v
or +7.2V

[3zuli]

what diode are you using?

[Electorials]

"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]

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

[Electorials]

Ok.

And what is the average efficiency value of a DVD burner diode?
(Output power / Input power)

[3zuli]

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]

Ok, Thank you ;)

[HFraza]

how to make it without module

[HFraza]

please tell me the voltage of laser burner

[cas2406]

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]

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

[cas2406]

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]

do u really need to use a module?

[3zuli]

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]

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

[The nerdling]

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

[instructanator]

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]

of course, the power supply has to be powered on while adjusting the current

[instructanator]

Yea, that was a little stupid of me. Just making sure.

[instructanator]

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]

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]

Thank you!

[Dimitrioptimus]

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]

those lenses won't give you a dot, but a line or cross. to get a dot shaped beam, you need this:
http://www.modwerx.com/shop/laser-modules-spare-lenses-c-12/laser-focusing-module-for-5-6mm-laser-diodes-adjustable-focus-p-11?zenid=9sdhugjbn2mlu9l9iofhho6mf1

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]

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


thanks in advance...n sorry for asking out of syllabus qestions

[3zuli]

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]

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.

Thankx in advance

[3zuli]

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]

thanks for posting this - very useful.

[jmcvay]

a file only cuts going one direction, you will dull it going both

[kelseymh]

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]

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]

Yeah, I can see it as still quite useful