Laser Diode

[samarsingla]

Hi,
I have bought a laser diode from a hobby shop. It has three leads. Sshouldnt a diode have two? I am a bit confused. Can some one tell me the basics of laser diodes?
Thanx.

 

[audioguru]

Google has lots of information about laser diodes. The 3rd wire on yours is probably a built-in photodiode for brightness feedback.
You should get the datasheet for your laser diode or return it and buy one that has a datasheet.

 

[Nigel Goodwin]

If it has feedback you need to be VERY careful how you drive it, the difference between working and destruction is very small!.

 

[HiTech]

As Nigel points out destruction is an issue. My laser diode punched a hole through 3/4" high-carbon plate steel. If it wasn't for the styrofoam panel that just happened to be lying behind it, I would've lost my wife's curio cabinet full of Hummel figurines as well as the 6" thick wall of my home. All that from a 3 volt source!

 

[jbeng]

I think Nigel was referring to the laser diode being destroyed - not collateral damage to property ...
JB

 

[HiTech]

Duuuh, like I misunderstood him just as you misunderstand me!

 

[HarveyH42]

It would would be cool as hell to etch with a laser pointer, but last I looked, the best you can do is pop balloons...

 

[jbeng]

Personally, I didn't misunderstand you, as I don't misunderstand much. But I was hoping that samarsingla wasn't misled into thinking he could be severely injured by the laser based on your exaggeration.
JB

 

[samarsingla]

Thanx all for the feed back. How should I get this diode working? I want to get pulses of laser beam using a microcontroller. Do i need some other parts? What exactly do these do-
https://focus.ti.com/docs/prod/folders/print/onet4201ld.html ?? Please give me some link if someone knows of a good link as most of the links I got on google are commercial products not much informative...

 

[audioguru]

You look at the datasheet for your laser and select parts for the driver IC to match its ratings. It is easy if you have the laser's datasheet.
If you don't have the laser's datasheet then either it won't work like a laser or it will blow up.

 

[samarsingla]

I don't have the data sheet. Any help in that case?

 

[audioguru]

I don't have the data sheet. Any help in that case?

A laser diode without a datasheet is nearly useless!
You could GUESS at its ratings and maybe you'll be lucky and it will work.

 

[picasm]

You also need to be very careful as there is a possibility that this unknown laser diode could be an Infra-red type as used in laser printers or cd players.

An invisible infra-red laser beam can still cause permanent eye damage!

 

[HarveyH42]

Maybe this link will help...

**broken link removed**