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Need clarification on how a laser works? And how to build my own.

zastin17

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So I've been experimenting with lasers and I am wanting to build my own. So from my understanding. You have a laser Diode. Which is wired to a voltage regulator or voltage converter. Something to bring the voltage to match the specs of the diode. Which is then behind a lens at the correct focal distance. Then obviously a switch.

I also understand from the dissection of my green laser, that the diode is not a 532nm, but is an infrared diode which is somehow passed through a filter which converts it into 532nm. 532nm diodes don't exist. 520nm ones do however.

So If I where to purchase lets say an Oclaro https://www.ebay.com/itm/Oclaro-HL63193MG-638nm-700mW-Orange-Red-Laser-Diode-1-pcs-/332422170570?_trksid=p2349526.m4383.l4275.c1#viTabs_0HL63193MG 638nm 700mW Diode.
Wire it to a voltage step down converter which is powered by an 18650. Bring the voltage down to around 2.3v and wire it to the diode. Would it work? Then obviously finding a way to mount it behind a laser lens at the correct focal length.

I also know that diodes get hot and must be installed onto something to wick the heat away.

Also do you need different lenses for different colored diodes?

I would really appreciate it if someone could clarify if any of the above is wrong or add onto it.
 
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Cyparagon

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The best option for you at this point is to google "laser pointer tutorial build" or something to that effect. All of your questions will likely be addressed. If you still have questions after looking through a few tutorials, that would be a better time to ask them.
 

Gazen

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You need a constant current source to drive a diode, not a constant voltage. Different lenses are often needed for different lasers as they have ar coatings for different wavelengths.

If you were to buy that diode, you would need to press it into a module, find a driver for it, probably a buck because the diode has a low vf, and then you’ll need to put the module into a heat sink if you’d like a decent runtime.

You are correct about the 532, it is dpss( diode pumped solid state). I believe that it uses a 808nm diode that pumps nd:yag, which lases into a ktp crystal which doubles the frequency. Including these crystals elements there are also lenses and typically an ir filter.
(I’m still new to this hobby, if I’m wrong please correct me)


Also, please make a post in the welcome section introducing yourself.
Welcome to the forum! :beer:
 
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First Read Laser safety.
And buy a good trusted Laser Safety Glasses.

Im still new to this level of lasers myself. Please do a Intro post about yourself.


So I've been experimenting with lasers and I am wanting to build my own. So from my understanding. You have a laser Diode. Which is wired to a voltage regulator or voltage converter. Something to bring the voltage to match the specs of the diode. Which is then behind a lens at the correct focal distance. Then obviously a switch.

Its not really a voltage regulator. You want to limit and control the Current (a constant current source) that drives the diode. This helps to prevent thermal runaway.

I also understand from the dissection of my green laser, that the diode is not a 532nm, but is an infrared diode which is somehow passed through a filter which converts it into 532nm. 532nm diodes don't exist. 520nm ones do however. If there is not a IR filter then the output will be at a higher power

So If I where to purchase lets say an Oclaro https://www.ebay.com/itm/Oclaro-HL63193MG-638nm-700mW-Orange-Red-Laser-Diode-1-pcs-/332422170570?_trksid=p2349526.m4383.l4275.c1#viTabs_0HL63193MG 638nm 700mW Diode.
Wire it to a voltage step down converter which is powered by an 18650. Bring the voltage down to around 2.3v and wire it to the diode. Would it work? Then obviously finding a way to mount it behind a laser lens at the correct focal length.


I also know that diodes get hot and must be installed onto something to wick the heat away.
yes a heatsink. think there call a Host?(im new)


Also do you need different lenses for different colored diodes?
I dont think so, But there are AR coated lenses that increase the lens pass though effecancy and reduces reflection and back reflections into the laser optical cavity that can damage the laser.

I would really appreciate it if someone could clarify if any of the above is wrong or add onto it.
 
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paul1598419

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First of all, you should make an introductory thread and tell us a little about yourself and where you live. Secondly, direct diode lasers are only one class of many different types of lasers. The drivers do not step down or regulated voltage at all. They regulate current as the forward voltage of a laser diode tends to change with heat. There is no filter in a diode pumped solid state 532nm laser. It uses a Nd doped crystal to laser at 1064nm and another crystal, usually a KTP, which frequency doubles the 1064nm to 532nm. There is much you have to learn about lasers, Grasshopper.
 
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Encap

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First of all, you should make an introductory thread and tell us a little about yourself and where you live. Secondly, direct diode lasers are only one class of many different types of lasers. The drivers do not step down or regulated voltage at all. They regulate current as the forward voltage of a laser diode tends to change with heat. There is no filter in a diode pumped solid state 532nm laser. It uses a Nd doped crystal to laser at 1064nm and another crystal, usually a KTP, which frequency doubles the 1064nm to 532nm. There is much you have to learn about lasers, Grasshopper.
Exactly paul1598419

zastin17:
Good advice is to google the subject and then come back and ask questions as Cyparagon mentioned above.

Please make a Welcome thread in the Welcome subforum telling something about yourself and put your location in your profile.

See what a DPSS green 532nm is here: https://en.wikipedia.org/wiki/Diode-pumped_solid-state_laser.

See Survival laser if you want an idea of how to build a hand held laser pointer: https://www.survivallaserusa.com/

You can use the LPF Custom Search at the bottom of the page to find information and tutorials in the LPF database
 
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diachi

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Plenty of guides on here, do some digging. :beer:

Laser diode drivers are current regulated, not voltage regulated. Do some digging to find out why. :)

You need a constant current source to drive a diode, not a constant voltage. Different lenses are often needed for different lasers as they have ar coatings for different wavelengths.

If you were to buy that diode, you would need to press it into a module, find a driver for it, probably a buck because the diode has a low vf, and then you’ll need to put the module into a heat sink if you’d like a decent runtime.

You are correct about the 532, it is dpss( diode pumped solid state). I believe that it uses a 808nm diode that pumps nd:yag, which lases into a ktp crystal which doubles the frequency. Including these crystals elements there are also lenses and typically an ir filter.
(I’m still new to this hobby, if I’m wrong please correct me)


Also, please make a post in the welcome section introducing yourself.
Welcome to the forum! :beer:
Small nitpick. Just about all 532nm pointers these days use Nd:YVO4. YVO4 is more efficient than YAG in the configuration used for a pointer (polarized pump, longitudinal pump input). Otherwise you are correct.

The Nd:YVO4/YAG in a 532nm pointer lases at 1064nm when pumped with 808nm light. That 1064nm light is frequency doubled (wavelength is halved) to produce 532nm light.


 

Bacon

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I like buck drivers for higher powered diodes.

Good luck deciding on a host for it all. Once its done you will just want more. :)
 

Lifetime17

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Hi,
Welcome to LPF, but yes first things first a nice into would be nice so folks can help. And It would be also nicer if you add were your from and tell a little about yourself.
Safety is a must and you will need a good pair of safety glasses. Use the search bar in white it has an abundance of info on all kinds of topics.

Rich:)
 

zastin17

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So would something like this would work as a driver? https://www.ebay.com/itm/5A-Lithium...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

I also just purchased a 445nm M140 A 1.6W diode to experiment with.

So when adjusting the current would I just put a load on it and measure the amps with a multmeter and adjust to the desired MA? like this? https://www.electronicshub.org/wp-content/uploads/2015/09/Current-Measurement.jpg

And since the current is constant does that mean I can use any load. I don't wan't to do this with the diode as it could burn out if set to high by default.


And for a host I have one I had from a previous laser that burned out. Everything unscrews so I can install whatever I wan't
I also have a 3D printer I built I could use to design and print custom hosts. Its goes down to 50microns so I could even print threads for the module if I wanted. Planning to use high temp carbon fiber filament.
 
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Encap

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No--that driver is not laser diode driver-- that driver is an LED driver. Did you even read the title of the eBay listing?
LED drivers are not laser drivers. LED's are tough as nails but laser diodes are much more sensitive and need extra features like soft start, overshoot protection and a very low noise output that are standard on laser drivers but not included on LED drivers.

I know you are new pn LPF but you can easily find real world answers yourself. Takes some time to educate yourself about lasers beyond getting stuck at " I also just purchased a 445nm M140 A 1.6W diode to experiment with". It takes a bit more knowledge than that.

Since you seem to have little idea of the reality what you are talking about and imagining -- here is a head start:

See/read/strudy this " I want to build a laser" here: https://laserpointerforums.com/f51/i-want-build-laser-thread-52972.html#post740462

See all about M140 diodes -you can also buy any of them there as well --and find out all about diodes, drivers, lenses, and modules for diodes on this web site--here: https://sites.google.com/site/dtrlpf/home/diodes/445-m140-didoes

See how to build a basic laser driver and test load here: https://laserpointerforums.com/f67/laser-driver-can-done-rog8811-87507.html#post1273373

Eye safety is the #1 priority with lasers. Lasers are not toys --they are dangerous and can cause permanent eye damage in a split second-- less the the human blink reflex time of 0.25 seconds.
See good laser glasses/googles here: https://www.survivallaserusa.com/Safety_Goggles/cat1667093_1527285.aspx

See this thread of about eye damage caused by a 445nm 1W laser: https://laserpointerforums.com/f53/hit-eye-1000mw-445nm-blue-laser-69469.html

Read up on/study laser safety on this excellent web site : http://http://www.laserpointersafety.com/

See Laser Hazard chart here: http://www.lasersafetyfacts.com/resources/FAA---visible-laser-hazard-calcs-for-LSF-v02.png
 
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