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FrozenGate by Avery

Help on 808nm 300mW

MA257

MA257

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Mar 25, 2011
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Hey i'm new here and new to laser projects. But i'm having issues with my first laser project. It's a 300mW 808nm laser running off a 9v battery of this schematic. The problem is that the light is barley visable or bright even at the rheostats full capacity. I've gotten the voltage at 7.5v. I'm trying to make it burn but i am failing. Could someone please help, Thank You

Schematic.png


(ignore the LED thing this laser is also attached to another project but 1 power source)
 
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I don't quite follow your circuit - but the easy answer is that you're building an 808nm laser. The light shouldn't be visible. That's infrared, which is not a wavelength our eyes see.

Look at the top of a television remote control - those signals are infrared too, but you don't see them right?

This is a really dangerous project to be undertaking. 300mW of infrared laser light will damage your vision without safety goggles, and I'm going to guess that you don't have infrared laser safety goggles on?
 
yeah i know but how come it doesn't burn though?
oh and the circut it 2 common homebuilt drivers put into 1 but it only uses one at a time.
 
What lens are you using to focus the 808nm laser diode? Attach a photo of your setup.

Again - do you have infrared laser safety goggles?
 
No I do not have goggles but i assure i haven't been staring in the light and i am using a standard 12x30mm axiz module casing with a glass lens. here is a picture of my setup. the doide hasn't been soldered in yet though.

DSCN0880.jpg
 
You will only dimly see 808nm IR, so how in the Hell are you going to focus it to a micro-spot??? Getting close enough to even attempt to see the spot You WILL certainly damage your vision. An IR Laser is not one for a Laser Noob, and especially a Laser Noob who won't get safety glasses. Put this Laser away and buy a 10mW green maybe You can handle that!!
 
I'm using an IR vision system and it isn't a dot but a line whats's wrong now?
I've focused it as much as I can but still got nothing. Is there enough power going to it?
 
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when you guys say "damage your vision" does that mean looking directly into the laser (accidental reflection)
or just by looking at the invisible "dot" on a white wall?
 
A couple problems...
1- Those diodes are meant for pumping, not a nice beam, the output is ugly.

2- If its sold as a 300mW, and not a 500, chances are its being run at is maximum
output. With that strip of tape wrapped around the module it wont last long
insulating all that heat.

Search the forum, do some reading and maybe start with a visible laser to get
the hang of things..

If you want NIR with a good beam, use a 780nm LD from a CD burner..
 
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It hasn't been producing any heat at all but yeah you might be right thanks
 
What current are you running the LD at? What are the specs
from the seller?

You need to test the amount of current firstly... Some
basic tests are needed to figure out what the problem is.
 
Umm, Im running it at 9v and i ordered it offline and got nothing in the package all i know is that its operating voltage is 2.2v at CW 300mW but i'm running them at a constant 7.5v through the driver using the 100ohm trimmer circut.
 
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MA257 said:
Umm, Im running it at 9v and i ordered it offline and got nothing in the package all i know is that its operating voltage is 2.2v at CW 300mW but i'm running them at a constant 7.5v through the driver using the 100ohm trimmer circut.
Click to expand...

You need to know what the current across the LD is, not the voltage. Go read around on the forum a bit and come back because trying to diagnose whats wrong with the laser from a poor picture, vague information and a diode that isn't a standard one is next to impossible. It could simply be you've put your circuit together wrong.

And to be honest why even bother with iR? It's pointless and dangerous. Go look on stonetek.org, hightechdealz.com or something and find a coloured diode. Some of them are dirt cheap and it'll be a lot easier for people to help you out as you can just use the standard LM317 driver you find on the forum alot.
 
Echo the ^ above sentiments 100%. Why bother with IR? It's not a rewarding direction to go in.

And frankly, it's semi-terrifying to me that so many new entrants to the hobby are jumping in on IR lasers these last few weeks. Makes me wonder if there has been a recent kipkay about making invisible laser weapons...

On the bright side, judging by the photo of OP's setup, and his lack of heatsinking, I'm betting his diode has been fried a few times over by now :)
 
yeah well i didn't mean to get the IR i actually wanted a 65onm but couldn't find one cheap so it seemed my option was these 808nm but i'll read around and get some knowledge hopefully fix the issue. But I assure you that circut has been triple checked and more i think its the diode. thanks for all the help.
 
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