First red LD murdered. And a few questions.

[a_pyro_is]

Well, I've done it now. Murdered my first diode... :'(

I was give a dead DVD drive and promptly tore it to shreds. I was rewarded with a beautiful new (to me) LD. I didn't have a module to put it in so I was just holding the diode in it's heatsink/mount from the drive, with a lens from an old <5mw $1 pointer. It seened to reach threshold at around 40ma and when I put 110ma in it it would instantly pop balloons and slowly cut electrical tape.

Well, I decided that it wasn't enough for me...so I slowly started raising the current and at about 145ma it suddenly got much dimmer and instead of one BRIGHT red bar it now has three dim bars.

Is this the COF of which I've read?

If I can figure out why PayPal checkout isn't working for AixiZ I'll order a few modules and get some of the SenKat GB Diodes.

And to add a few more questions. How much juice is everyone driving the GB diodes with? It sounds like somewhere between 80ma and 250ma. But has anyone pushed them farther?

Thanks,
Matt

 

[Hemlock_Mike]

How much current depends on the DVD drive -- 12x 16x 18x ???
The slower the drive, the lower power it will have. Yours may have been older and wasn't made to be pushed that hard.

Mike

 

[SenKat]

They have been pushed up to 600ma with TEC cooling, but no discernable increase was noticed beyond 400ma.

G !

 

[Things]

3 lines? when i ripped the ps2 apart(i know, the laser isn't high powered) the lasers output was 3 lines?it was an open can with some other stuff inside.

 

[Benm]

so I slowly started raising the current and at about 145ma it suddenly got much dimmer and instead of one BRIGHT red bar it now has three dim bars.

Is this the COF of which I've read?

Probably, sounds like you pushed it too far, and blew the internal mirroring facets to bits. The remaining diode still produces like in the same fashion a LED does, but is unable to lase without its mirrors. You'll notice that the light output doesnt speckle anymore. The 3-line pattern is probably just a result of the damaged facet on the output side of the laser.

They have been pushed up to 600ma with TEC cooling, but no discernable increase was noticed beyond 400ma.

Good to know that those diodes are THAT sturdy... the curves in the datasheet stop at 300 mA or so, right?

Some diodes are really sensitive in that respect, especially the cheap 5 mW-ish ones... i've seen them with the treshold at around 15 mA, and total failure at 25.

 

[styropyro]

I've got the three line effect when I have fried a 16x diode and a cheap 5mW diode, and power is about the same too! I don't know what the lines come from, but I guess it's from too much current frying out the poor diode's insides.

 

[Gazoo]

As much as I loved your video, I think a little more circuitry may have helped.. ;D

 

[styropyro]

As much as I loved your video, I think a little more circuitry may have helped.. ;D

You are probably right about that, I should have added a capacitor or something, but that little one I made in the video is still working for me without a capacitor. The first one fried when I tried putting it in an Altoids tin and something shorted to bypass the pot and I had a dead diode, but luckily I had a second diode as a backup and I decided to make a video of it lol.

 

[Gazoo]

Well you are lucky.. ;D It just goes to show that each diode does have it's own personality. Some diodes behave and others throw up..