CdRw Laser Diode Questions

Hi to all I started today to experiment with lasers from old cds or Dvds...I have some basic electronics knowledge....

So,today i opened an old Yamaha CRW6416s CD-RW and took the laser diode out...I put the diode in an aixiz and tested at about 2 volts...I could see the red light even that i know it is 780mm...

Anyway,what i want to ask you is :
First, Where can i found how much power output this diode has?How much voltage should i put?How much current?Generally i need a datasheet

Secondly,i have a smal LM713 power supply...Is it enough to control this laser or i gonna destroy it?What is the simplest controller i can build?

Thanks a lot to all and Happy New Year

Hello Nuke!

Did you mean that you are using the LM(317)?

Were you using voltage regulation mode? Or current regulation mode?

At 2V, your diode could have been pulling any amount of current...

Remember that it's the current that determines the output of the diode, not the voltage..

I can't seem to find any information about the drive that you pulled the diode from... but I've had a little luck with about 250ma-300ma of current.

Do you mean that you can't get the dot focused to a good distance using the aiXis module?

I hope this helps...

-Tyler

If you have a video camera or a still camera with live preview, the camera can probably see IR quite well. This will help you focus. If the diode is from a fast cd drive, it should be able to light matches and cut black tape once you can find the focus. Make a current regulator (DDL) with your LM317 and set it to 200mA to start. (a 6.8 ohm resistor gives about 183mA, a 5.6 ohm gives about 223mA) Use the camera to confrm lasing and as a focusing aid.

Bill, such IR lasers almost always cause the 'lens flares' in cameras, and it is almost never possible to use as focusing aid.

And yes, OP:
LM317 should be used as current regulator, with a total of 6.8 ohms of resistance between middle (out) and left (ADJ) pin, forget the potentiometer.
You should be able to see a fair amount of reddish light, without the camera, and it will be very good burner, at aproximate output of 150 mW of power.

However! Be extremely careful! I once used such IR diodes to make a fancy firecracker lighter two years ago. After waking up with a blurry and ichy spot in my right eye the next day, it did NOT TOOK a God's sign for me to realise that it was not a toy!
I dissasembled the bloody thing in two minutes, hammering the diode out of aixiz included.

So, take EXTRA care with IR!!!

First of all thanks to all for your replies...

Yesterday,i operated the laser with an LM317 current limiter.I managed 153ma at 2,50 volts and it succeded to fire maches with black heads Also it burns black plastics easily

I think it may go even further but i dont want it to be destroyed....

Eudaimonium, in order to be harmed,dont u need to look direcktly in the beam?

Is it possible to damage yourself by reflections?

Thanks a lot

P.S. Yes,you can see a red spot even if it is infrared

NUKE said:

First of all thanks to all for your replies...

Yesterday,i operated the laser with an LM317 current limiter.I managed 153ma at 2,50 volts and it succeded to fire maches with black heads Also it burns black plastics easily

I think it may go even further but i dont want it to be destroyed....

Eudaimonium, in order to be harmed,dont u need to look direcktly in the beam?

Is it possible to damage yourself by reflections?

Thanks a lot

P.S. Yes,you can see a red spot even if it is infrared

Click to expand...

Well, specular reflections are enogh to make you blind.
You see, that is not a mirror reflection straight on, it is like,.. shining it on a metar surface.
Reflected beam will be heavily distorted and scattered, but CAN do damage to your eyes!

IR diodes from DVDs and CDs have been measured thouroughly by billg519, with his permision I can post his meaurements. I believe a safe current to run those is about 200 mA, which equals in total resistance of
6 ohms between OUT and ADJ, if you want to set it properly, use a fixed resistor there, without potentiometer.

I know you can see a red dot, it is 780 nm, and we can all see a red dot from 808nm still, however beyond that is up to each individual.
I've heard of people that cannot see 405 nm violet, their eyes are already nonresponsive at that wavelenght.
I consider myself lucky to be able to see that beautifull color laser