100mw Diode dead, or driver issues?

Hey guys,

It's been a long time since I've posted here and I'm rusty with lasers in general now. After someone (points the finger at his missus) broke my green laser diode by trying to force the wrong battery into it and breaking the driver off along with the legs of the diode, I finally got around to buying a new diode from o-like.

The diode arrived yesterday and worked perfectly, today I stripped it down again to set the pot to a medium range so as not to burn the diode out too quick. When I put it back together and turn it on the laser is now extremely flickery for the first second of powering it up, it stabilises by itself but it's dim... and by dim I mean barely noticeable.

As I'm stupid I had a peek at the lens (not directly into the beam and with glasses... but still, stupid I know) and it's emitting a noticeable red light, I vaguely remember my old one doing this when the pot was too high.

It's supposed to be 100mw, yesterday it seemed bright enough to be 100mw but I no longer have any equipment to measure its output, as all of that went a long time ago along with my argon lasers when I had to move house.

Any ideas if I might be looking at driver issues or a dying/dead diode?

Might note I've messed around with it since starting writing this and managed to get it a little bit brighter, but it's flickering pretty badly.

I've re-soldered switch contacts, pot contacts, diode legs etc.. but nothing seems to have made a big difference yet.

EDIT - Diode is dead I think, it has ceased outputting any green light and seems to only emit a very weak IR light (seen through a camera), tinkering with the pot does absolutely nothing.

I'll need to find a new use for my 20 CR123's now xD

sounds like a driver problem. generally diodes don't flicker or anything, they just die (at least i've never heard of flickering in a direct diode laser with stable current). you should probably get a new driver as well, or send it to a forum member who can check out whats happening to it. also, welcome back! its been more than three years since you last posted... holy crap!

Thanks for the reply Micheal!

Would a dead 532 diode output a weak IR light? that's all it does now, it's had no reflection damage that I'm aware of, nor has it been shocked/dropped, never really had an issue like this one before...

I'll see if o-like will send a new driver out to me, I'd make my own but seeing as this cost me and it appears to have failed I'll try them first.

Thanks for the welcome, it's nice to be back to be honest

Link said:

Thanks for the reply Micheal!

Would a dead 532 diode output a weak IR light? that's all it does now, it's had no reflection damage that I'm aware of, nor has it been shocked/dropped, never really had an issue like this one before...

I'll see if o-like will send a new driver out to me, I'd make my own but seeing as this cost me and it appears to have failed I'll try them first.

Thanks for the welcome, it's nice to be back to be honest

Click to expand...

Oh, it's not a diode laser, it's a DPSS laser. The diode is emitting infrared light, and then a set of laser crystals "converts"it to green light. The crystals somehow became unstable, who knows why, there could be a million reasons. Youre better off getting a new laser if that's the case.

micheal rosen said:

Oh, it's not a diode laser, it's a DPSS laser. The diode is emitting infrared light, and then a set of laser crystals "converts"it to green light. The crystals somehow became unstable, who knows why, there could be a million reasons. Youre better off getting a new laser if that's the case.

Click to expand...

I knew green lasers emitted high levels of IR... what I didn't know was that they are DPSS IR lasers using crystals to create the correct wavelength... I thought only blues used that, hence the price tag on the blues!

Thanks

Link said:

I knew green lasers emitted high levels of IR... what I didn't know was that they are DPSS IR lasers using crystals to create the correct wavelength... I thought only blues used that, hence the price tag on the blues!

Thanks

Click to expand...

Yeah. The 532nm dpss ones are really simple, since the strongest transition line of the Nd:YAG or Nd:YVO4 crystal is 1064nm, and KTP crystals are efficient at doubling that wavelength at room temp, the whole process is fairly efficient and the crystals can use inexpensive coatings.

In 473nm lasers, the crystal has to be forced to emit a different transition line (946nm) with special coatings that are more expensinve. This also makes the laser less efficient and the use of crystals other than KTP (since it isn't efficient at those wavelengths) doesn't help the price either.

DPSS 101 - Thanks Micheal

On the note of blues, the price has dropped significantly since I last looked, by almost half...

Thanks again for the info, I'm in contact with o-like for a replacement diode

Link said:

DPSS 101 - Thanks Micheal

On the note of blues, the price has dropped significantly since I last looked, by almost half...

Thanks again for the info, I'm in contact with o-like for a replacement diode

Click to expand...

Yeah, no problem. There's also a laser diode that emits at 470nm... and 5W of power! Its only $140 at DTR's laser shop, so building a laser out of it would be like $250, insane right?

micheal rosen said:

Yeah, no problem. There's also a laser diode that emits at 470nm... and 5W of power! Its only $140 at DTR's laser shop, so building a laser out of it would be like $250, insane right?

Click to expand...

I may have to try it...

Try a 520nm green, they are direct diode, they don't break easy and aren't temperature sensitive like a 532nm DPSS.

Alan