Checking broken laser diode

[hozone]

Hello,
I've two laser diode possibly broken.
All laser is tested in a close box using a webcam (a.k.a. eye security ).
One is a IR from a CD-RW, it absorbs current from 10mW to 15omW, but emit low light, as comparison i've other IR from CD-RW, up to 30mW laser beam begin to blind the webcam sensor, so i suppose this one is broken, could it be?
The other one i do not know which type of diode is, i've tried different pinout. It only suck current but do not emit any light.
For this last one the question is the same, it is possible that a diode absorbs current but do not emit light? I mean, i thought that a broken diode does not absorb current.
thanks!

 

[Alaskan]

I have a bad laser diode which died from an over voltage accident which draws current, but does not emit any light.

 

[The Lightning Stalker]

If a laser diode is connected backwards, it
will draw current because of the low
reverse voltage, but not give any light.
It will also be permanently ruined.

 

[hozone]

Thank yours replies.
So, in short, they could be actually broken.
I usually test diode using a LM317 powered @ 9v, starting up from 5mW, testing pinout. If the diode asbsorbs some current with the select pinout, then i turn the LM317 driver pot up and i test with more current. Is it a good method?
Thanks again.

 

[ChaosLord]

No, that's not a good method to test a LD. Micro amps can kill a laser diode. The way I've seen to do it is to slowly feed voltage into it to up to ~2V. I've seen this and other methods posted around here.

 

[hozone]

tks!

So:
1] Do a pinout/wiring
2] Feed slowly voltage from 0 to 2V
3]
IF diode absorb current THEN that's the correct pinout
ELSE the pinout is wrong
4] check other pinout (back to 1] )
5] IF not pinout works, THEN the diode is broken

right?

 

[The Lightning Stalker]

2V is cutting it pretty close. It should begin
to do something at 1.5V, depending on the
diode.